Sea Ice Stretch Run #2

1. ared
Posted Jul 23, 2008 at 11:37 AM | Permalink

Joshua, you’re right of course, but all other extend changes in history have also included compaction. And as far as I can tell (the IARC-JAXA data starts in 2002 and the Cryosphere graph is useless for this), there has never been a day with an extend decrease of more than 202.000 km^2 per day. You are suggesting three days of 250.000 km^2 average per day. Is that proof it won’t happen? No. But I’ve always been taught that you should be very careful when predicting stuff that’s never happened before, and what you’re predicting dwarfs that.

Here’s a grafic of what you’re predicting: graph

Possible? Maybe. Likely? I think not. All the more credit to you if this one turns out as you predicted.

2. Pierre Gosselin
Posted Jul 23, 2008 at 12:29 PM | Permalink

Looking at some average high temperature for various northern hemisphere cities, many occur on about July 20th. After that they slowly start receding, and start to fall rapidly at the end of August – mid September.
The peak of the summer heat is now behind us.
And looking at the following NH sea ice extent:

I’d say time is beginning to run out for those who boldly predicted less sea ice than last year.
Actually, last year’s sea ice melt season extended very late into the autumn. This situation most likely will not repeat itself.

3. Pierre Gosselin
Posted Jul 23, 2008 at 12:45 PM | Permalink

ared,
Very interesting graph. Indeed the rapid ice melt that occurred early July 2007, would have to be repeated at least 7 days in order for 2008 to catch up to 2007. Next, the very unusual wind situation that took place last year in September would also have to repeat itself. Possible? – yes. Probable? – very improbable.

Also keep in mind that the global temps are now about 0.6°C cooler than a year ago. I think this means an ice melt season that is going to be a few days shorter. Finally I doubt there are many scientists left who are ready to put “big money” down saying that 2008 will have a greater ice melt than last year (except for maybe the high rollers at RC, but not without back-out clauses).

4. Posted Jul 23, 2008 at 12:49 PM | Permalink

Re #3

I fail to see the logic behind a dependance of the Arctic Ice melt season on global mean temperature, talk about teleconnections!

5. Douglas Hoyt
Posted Jul 23, 2008 at 1:09 PM | Permalink

The Barrow Sea Ice webcam shows ice off the coast of Barrow right now.

6. Posted Jul 23, 2008 at 1:26 PM | Permalink

Re #5

So do the satellites.

Posted Jul 23, 2008 at 1:47 PM | Permalink

Looks like Barrow is getting a wintry mix. Saw some news footage of that Senate trip to Prudhoe from a couple days ago. There was a front moving in – even in the southerly flow they were wearing the type of clothing that indicated it was in the upper 40s or low 50s F, max.

8. Gene II
Posted Jul 23, 2008 at 6:03 PM | Permalink

Re : Steve McIntyre

Just a request : is it possible for you to post an updated spaghetti graph (updated from the above graph of julian day 182)? It would be interesting to see the movement of the black 2008 line up until today, julian day 203.

9. reid simpson
Posted Jul 23, 2008 at 6:25 PM | Permalink

When it doesn’t do as it is supposed to do, it is, of course, of no consequence.

10. DeWitt Payne
Posted Jul 23, 2008 at 6:27 PM | Permalink

ared,

I’m not saying that 2008 will catch up to 2007, I’m saying it might catch up. We won’t know for sure until the loss rate starts to decrease. It hasn’t yet. It certainly will soon. The question is, when is soon? It’s already later than the recent average.

An EWMA chart isn’t a predictive tool. It tells what has been happening and it’s quite sensitive to small changes in trend.

11. TAC
Posted Jul 23, 2008 at 9:03 PM | Permalink

Preliminary Unofficial Day 205 Race Report
2008 had another day with melt exceeding 100000, apparently exceeding 2007 and every other year since 2001.
7 24 2002 8.120000 -0.113281
7 24 2003 8.171563 -0.106562
7 23 2004 8.543125 -0.042031
7 24 2005 7.612969 -0.075937
7 24 2006 7.597969 -0.027031
7 24 2007 6.858125 -0.113906
7 23 2008 7.764063 -0.119062

12. AndyW
Posted Jul 23, 2008 at 10:48 PM | Permalink

2007 had a few slow days in the coming week but then a few 100k + days so really 2008 needs to have it’s late surge this week or next to make any impact. High pressure regions seems to be expanding through the week whilst recently a lot of LOWS from extratropical storms, ie Bertha have been going NE past Iceland and the Denmark straight.

13. Steve McIntyre
Posted Jul 23, 2008 at 11:09 PM | Permalink

#11. Interesting, that’s a pretty big day. Some commenters have given plausible reasons why the melt might continue to be strong longer this year. For reference, I counted the number of plus-100,000 sq km days after julian day 200. We;ve had 2 in 2008 so far.

2002- 3; 2003 -6; 2004 – 6; 2005 -4; 2006 – 0; 2007 -7; 2008 -2.

If I were to guess right now, I’d guess that we;ll stay at about 950,000 more than last year – which would be about 5.2 million sq km on the JAXA scorecard – each one being a bit different, which would still be a high melt year, but definitely not nearly as low as the new ice argument predicted.

14. crosspatch
Posted Jul 23, 2008 at 11:51 PM | Permalink

This year’s ice was “crippled” from the massive melt last year. The recovery was very impressive. I think it isn’t this year’s melt that is really going to tell the story so much as it will be this coming winter’s freeze. If the ice extent this winter goes into a positive anomaly from the average since 1979, the people predicting a soon to be ice-free arctic are going to be in a world of hurt. For me, I am more interested in what this winter brings than what this summer melt is going to do as it *is* to some extent handicapped by the state it inherited from last year.

15. jeez
Posted Jul 24, 2008 at 12:23 AM | Permalink

I have confidence the baby ice can do it.

Yooo can doooooo it!

Baby Ice! Baby Ice! Baby Ice!

16. Vincent Guerrini Jr
Posted Jul 24, 2008 at 1:33 AM | Permalink

#14 Yes its the winter ice NH that could go into positive anomaly. So “if” both SH (and SH is highly significant having persisted 11 months postive anomaly), and NH are positive we can speculate that we “may” be entering a cooling. “” = trying to copy agw’s because all they seems to produce is if’s, may’s and could be’s! LOL.

17. Luis Dias
Posted Jul 24, 2008 at 3:38 AM | Permalink

Perhaps Phil was right and we may start to see the “baby ice” to begin to collapse.

18. Filippo Turturici
Posted Jul 24, 2008 at 6:03 AM | Permalink

#8: Gene, you are talking about the day of the year (doy), counted as 1st January = day 1 to 31st December = day 365 (366).
The Julian Day is counted since 1st January 4713 BC (since the Greenwich midday if I remember it right) and today should be day 2454673.

http://en.wikipedia.org/wiki/Julian_day

Posted Jul 24, 2008 at 11:50 AM | Permalink

Re: 15

Nice! This thread needed a laugh.

Next Disney makes an animated movie about the baby ice sheets. Through will and determination they hold hands and manage not to melt all summer (after the mommy ice sheet gets killed in the first five minutes of the movie of course.)

20. Posted Jul 24, 2008 at 12:30 PM | Permalink

The overnight revision is shown below:

7 23 2008 7.764063 -0.119062 (original)
7 23 2008 7.772344 -0.110781 (revised)

21. BarryW
Posted Jul 24, 2008 at 12:32 PM | Permalink

Right now 2008 looks like it is tracking right in the middle of the pack for 2002 to 2006 here. To get below 2007 it looks like it would have to increase the rate significantly or continue melting into October.

Posted Jul 24, 2008 at 5:21 PM | Permalink

Stick a fork in it. The polar vortex is already champing at the bit to expand, as evidenced by unseasonably early outbreaks of cP air heading straight south. The North Atlantic is already showing Fall troughiness and the Gulf of Alaska low is already trying to throw out its own curveballs and inside sliders. There is no persistent ridge to the NW of the Chukchi Sea (which was one of the factors resulting in last year’s big open water north of Easternmost Siberia). I predict an unnnnnnnnnprecennnnnted early onset of climatic Autumn for a majority of the NH.

Posted Jul 24, 2008 at 5:28 PM | Permalink

AKZ204-251245-
EASTERN BEAUFORT SEA COAST-
INCLUDING…KAKTOVIK…FLAXMAN ISLAND
226 PM AKDT THU JUL 24 2008
.TONIGHT…CLOUDY. AREAS OF FOG. LOWS AROUND 35. NORTHWEST WINDS
10 MPH.
.FRIDAY…DECREASING CLOUDS. AREAS OF FOG IN THE MORNING. HIGHS
45 TO 50. EAST WINDS 15 TO 20 MPH.
.FRIDAY NIGHT…PARTLY CLOUDY. LOWS AROUND 40. EAST WINDS 20 TO
25 MPH BECOMING SOUTH 10 TO 20 MPH AFTER MIDNIGHT.
.SATURDAY…PARTLY CLOUDY. HIGHS AROUND 50.
EAST WINDS 10 TO 20 MPH.
.SATURDAY NIGHT…INCREASING CLOUDS. LOWS AROUND 45.
SOUTHEAST WINDS 10 TO 20 MPH.
.SUNDAY…MOSTLY CLOUDY. HIGHS NEAR 50.
.SUNDAY NIGHT…CLOUDY. CHANCE OF RAIN. LOWS NEAR 40.
.MONDAY…CLOUDY. CHANCE OF RAIN. HIGHS NEAR 40.
.MONDAY NIGHT…CLOUDY. CHANCE OF RAIN. LOWS NEAR 40.
.TUESDAY…MOSTLY CLOUDY. HIGHS NEAR 45.
.TUESDAY NIGHT…MOSTLY CLOUDY. LOWS NEAR 35.
.WEDNESDAY…MOSTLY CLOUDY. HIGHS NEAR 40.
.WEDNESDAY NIGHT…MOSTLY CLOUDY. CHANCE OF RAIN. LOWS NEAR 35.
.THURSDAY…PARTLY CLOUDY. HIGHS NEAR 45.

======================================

Also, Anchorage reported a record low maximum temp yesterday. The arctic is cooling earlier this year than it did last year. Here comes the ice baby! (As opposed to, there goes the baby ice … nyuk, nyuk, nyuk).

24. kuhnkat
Posted Jul 24, 2008 at 10:38 PM | Permalink

Phil,

when you gave your prediction based on previous numbers I stated all you had was funny numbers. Here is why:

http://www.sciencedaily.com/releases/2007/11/071113200545.htm

Past performance is a valid way to project, except, you need to take into account changing conditions.

25. DeWitt Payne
Posted Jul 25, 2008 at 12:26 AM | Permalink

7/24/2008 7.667188 compared to 7/25/2007 6.781250. Another 100,000+ day. Still no sign of a bottom in the melt rate curve. Another couple of days like this and the smoothed melt rate will exceed the smoothed melt rate at the same time in 2008. I would still need good odds to consider taking a bet that 2008 will match or exceed 2007, but the odds are getting somewhat smaller.

26. DeWitt Payne
Posted Jul 25, 2008 at 12:45 AM | Permalink

Here’s the EWMA smoothed rate for today
7/25 2003-2006 average -72846 km2/day not changing much

7/25/2007 -96038 km2/day and decreasing (absolute value)
7/24/2008 -88313 km2/day and increasing (so far. It could change at any time)

27. Posted Jul 25, 2008 at 12:55 AM | Permalink

Re #24

I’m not sure exactly what ‘prediction’ you refer to, however I wonder why it’s taken you this long to mention this document? The whole point of predictions is that one doesn’t know how the conditions will change so it would be very difficult to take them into account unless one were omniscient! Unlike you I make no such claim.
Why do you suppose that I was not aware of this paper and why do you suppose that it would make a difference?

Re #23

I was unaware that Anchorage had been transplanted to the Arctic ocean!

28. DeWitt Payne
Posted Jul 25, 2008 at 1:14 AM | Permalink

Assuming about 60 days until minimum extent, 2008 will have to average 14,800 km2/day higher loss rate to catch up to 2007. I’ll try to keep track of that number. Once this difference exceeds the daily loss rate, the race is pretty much over.

29. Chris
Posted Jul 25, 2008 at 2:31 AM | Permalink

Hey guys don’t panic!
We’re still about 880,000 km/2 behind 2007
If you look at 2007 it took 11 days from now to lose a further 880,000 km/2
Therefore, taking 2007 rates as a benchmark we are 11 days behind

07,25,2007,6781250
08,05,2007,5890469

(07,24,2008,7667188)

Except that of course we need to exceed 2007 rates to catch up. At the moment there is very little to choose between the rates, both averaging very close to -100,000 km/2 per day in the last 4 days.

But let’s imagine that the gap is closed from the current -880,000 km/2 to say -750,000 km/2 by Aug 5th

08,05,2007,5890469
08,18,2007,5166250
08,19,2007,5121563

We would then be between 13 and 14 days behind 2007 at 2007 melt rates. Once you get past mid-August the melt rates slow very significantly: to illustrate this think of how 2007 lost its final 3 million km/s

07,21,2007,7167656 i.e. 7.2 million km/2
07,25,2007,6781250
08,02,2007,6217500 i.e. 6.2 million km/2
08,16,2007,5241406 i.e. 5.2 million km/2
09,16,2007,4267656 i.e. 4.27 million km/2
09,24,2007,4254531

If this still doesn’t make you feel any more optimistic, then try checking out the following comparison between today’s polar ice and the same day in 1990:

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=07&fd=24&fy=1990&sm=07&sd=24&sy=2008

That’s one race that sure isn’t over!!!

Chris

30. Michael Jennings
Posted Jul 25, 2008 at 7:50 AM | Permalink

Thanks for continuing this from the old thread Steve! Phil, where are you getting your revised daily numbers so quickly?

31. ared
Posted Jul 25, 2008 at 8:41 AM | Permalink

revised number for today are in, large correction of extend up, so melt down.

07,25,2003,8070156,-101407
07,24,2004,8467813,-75312
07,25,2005,7559063,-53906
07,25,2006,7549844,-48125
07,25,2007,6781250,-76875
07,24,2008,7679219,-93125

still a big day compared to previous years, but below 2003 and below 100k. 7-day running smooth now basically flat compared to yesterday, could this have been the top of 2008? If there’s something to report about the EWMA, I’m sure DeWitt will let us know ;)

32. Posted Jul 25, 2008 at 9:37 AM | Permalink

Re #30

The same place Steve gets the extant data from: http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

33. jeez
Posted Jul 25, 2008 at 12:15 PM | Permalink

Lean to the left.

Lean to the right.

BABY, BABY, BABY IIIIIICCCCCCCEEEEEEE!

Posted Jul 25, 2008 at 12:25 PM | Permalink

Phil – That fact that you believe that I do not know the location of Anchorage says more about you than it says about me. The reason I brought it up, is because the conditions there are often a leading indicator of significant hemisphere scale shifts in synoptic conditions. It is also conveniently located so as to reflect very accurately the behavior of the Polar Front in the summer. You are not aware of these things?

35. Posted Jul 25, 2008 at 12:56 PM | Permalink

It looks like the Russians were wise to bail out of Station 35 two weeks ago:

Posted Jul 25, 2008 at 1:19 PM | Permalink

Will the NE island of Svalbard ever open up this year? Unnnnnnnnnnprrrrrrrrecedennnnnnnnnnnted!

37. Michael Jennings
Posted Jul 25, 2008 at 1:52 PM | Permalink

Phil, thank you.

38. jcspe
Posted Jul 25, 2008 at 2:09 PM | Permalink

July 25th, 2008 at 12:25 pm

Anchorage folks are very disappointed in this summer. It is reminiscent of the late 1970’s — much colder and cloudier than recent decades. Actually had new snow on the Chugach Mountains in July, which is very odd if not unprecedented. I have not talked to an old-timer that has a memory of seeing it before.

39. Posted Jul 25, 2008 at 2:58 PM | Permalink

Re #38

Despite the bad winter in Anchorage the seaice in the Beaufort sea has reached levels not reached in 2007 until ~2 months later so how good a predictor is that for the Arctic?

Re #36

Probably at the beginning of August like last year:

40. Posted Jul 25, 2008 at 3:02 PM | Permalink

41. DeWitt Payne
Posted Jul 25, 2008 at 4:30 PM | Permalink

Here is the corrected EWMA extent loss rate for 7/24/2008: 877110, slightly less than the initial estimate (88313), but still greater than the previous day. My expectation is that the rate will bottom sometime in the next week and then follow the behavior of previous years. In which case, the race is over. But until it does there is still a possibility that 2008 could gain significantly on 2007. Remember that the 2008 peak extent was higher than 2007 so the peak to peak difference could still be the same but the minimum extent for 2008 would not be as low.

42. DeWitt Payne
Posted Jul 25, 2008 at 9:56 PM | Permalink

Preliminary sea ice extent 7/25/2008 7.601250 km2, a loss of 77,961 km2 from the day before.

7/26/2007 6.688594 km2 a loss of 92,656 km2

That’s a slight increase in the difference. The EWMA loss rate decreased slightly to 86.196 km2/day compared to 95,700 km2/day in 2007. Insufficient data to say if this marks the turn or not. The next week should tell the tale.

Steve: Thanks. 2008 could easily catch 2005 and/or 2006, which make it #2. But it still looks like it will be a substantial step back towards the average despite the starting advantage of all the “new ice”. So it will be spun both ways as usual.

DAy 207:
month day year ice diff
7 26 2002 8.003594 -0.072031
7 26 2003 8.030000 -0.040156
7 25 2004 8.414219 -0.053594
7 26 2005 7.497344 -0.061719
7 26 2006 7.469844 -0.080000
7 26 2007 6.688594 -0.092656
7 25 2008 7.601250 -0.077969

43. David Smith
Posted Jul 25, 2008 at 10:37 PM | Permalink

Current Arctic insolation and 2002-2007 ice melt rate can be found here . The red dot denotes today (25 July). Insolation is into its rapid-decline stage while sea ice is near-peak.

44. DeWitt Payne
Posted Jul 26, 2008 at 1:10 AM | Permalink

A plot of the EWMA ice extent rate of change covering March 14 (day 73) to September 23 for the average of 2003 to 2006, 2007 and up to July 25, 2008 is here.

Note that 2007 was losing ice faster than the recent average well into September. If, and it’s only an if, the 2008 rate of change doesn’t decrease as fast as 2007, the gap could close significantly. Right now, the rate of change is greater for 2008 than the recent (2003 to 2006) average and the extent is lower as well.

45. DeWitt Payne
Posted Jul 26, 2008 at 2:49 PM | Permalink

Day 207 extent has been revised upward to 7.607969 km2 so the area loss decreased by nearly 10% to -0.071250 km2.

46. kim
Posted Jul 26, 2008 at 2:56 PM | Permalink

45 (DeW P.) That would start the daily loss rate on an upward trajectory. Are the polls closed? Can we call it?
=========================================================

47. jeez
Posted Jul 26, 2008 at 2:59 PM | Permalink

The Baby Ice is going to make it back home for Winter!

Soon they will discover that the Mommy ice wasn’t really killed in the first five minutes, it just appeared that way, she was just dazed and has been rotating aimlessly for months.

Happy Ending!

48. Pacman
Posted Jul 26, 2008 at 3:04 PM | Permalink

To #45: The race against 2007 is over, but 2008 has a 50-50 chance of overtaking 2005 and 2006, which would make it the second lowest extent on record.

49. crosspatch
Posted Jul 26, 2008 at 3:05 PM | Permalink

Well, there certainly doesn’t look like there is going to be a lot of surface melt at the pole today at least. Cloudy and 0C with some kind a precipitation going on.

50. crosspatch
Posted Jul 26, 2008 at 3:09 PM | Permalink

And looking at this graph it would seem to take a 9th inning miracle for 2008 to catch up with 2007. I don’t think it is going to be anywhere close by the time all is said and done.

51. DeWitt Payne
Posted Jul 26, 2008 at 3:53 PM | Permalink

kim,

It’s only one point and the data, even smoothed, is noisy. I want to see a run of at least 8 points with decreasing values before I even think of calling it. There was a run of 15 increasing points that was stopped by this point. Empirical extrapolation would still predict an increasing loss rate. However, the steady decrease in insolation will eventually force a decrease. I would not be surprised, though, to see the loss rate remains flat for a while.

52. Aaron Wells
Posted Jul 26, 2008 at 4:18 PM | Permalink

Personally, I still prefer to view the raw data (noise and all) rather than the smoothed data. For those who prefer the raw melt data, in positive values, click this link:

Sea Ice Melt Data Day 207

Also, here is the ice extent graphs for 2008, 2007, avg03-06, and 2005:

Sea Ice Extent Day 207

53. DeWitt Payne
Posted Jul 26, 2008 at 10:40 PM | Permalink

day 208
date extent(Mkm2) difference EWMA difference
7/25/2002 8.075625 -0.044375
7/25/2003 8.070156 -0.101407 -0.081332
7/26/2004 8.349375 -0.064844 -0.064448
7/25/2005 7.559063 -0.053906 -0.085175
7/25/2006 7.549844 -0.048125 -0.061701
7/25/2007 6.781250 -0.076875 -0.096038
7/26/2008 7.523906 -0.084363 -0.085378
2003-2006 average
7/25/200x 7.911719 -0.069688 -0.072846

The raw data shows greater loss than yesterday, smoothed very slightly less. The smoothed data has been essentially flat for 4 days. If it stays flat for two more weeks, 2008 could begin to make a run at 2007. Of course that also leaves 14 fewer days to catch up so it’s still very unlikely. 2008 is now ahead (or behind depending on how you look at it) every year except 2007. 2008 also started out with more ice extent than any year except 2003. So the baby ice theory has at least some support.

54. DeWitt Payne
Posted Jul 26, 2008 at 10:43 PM | Permalink

Started out isn’t exactly correct. It should be peak extent in 2008 was greater than any year from 2003 to 2007 except 2003.

55. agn
Posted Jul 27, 2008 at 2:05 AM | Permalink

DeWitt,

I think you are comparing with the wrong days – 2008 hasn’t caught up with 2005 and 2006 yet:

7/27/2002 7861094 -142500
7/27/2003 8003125 -26875
7/26/2004 8349375 -64844
7/27/2005 7386094 -111250
7/27/2006 7401250 -68594
7/27/2007 6594844 -93750
7/26/2008 7523906 -84063

56. kim
Posted Jul 27, 2008 at 4:37 AM | Permalink

51 (DeW P.) Yes, I agree. It is interesting that much of this year the daily loss rate has exceeded the average, but still trails last year. Also interesting is how close to the average melt rate last year was for August and September. So I agree, the baby ice still has a chance to melt like last year, but the lead looks too long to catch up, especially absent the winds which drove last year’s loss to such an extent. Last year, the melt rate was exaggerated to the extent that ice was pushed out rather than melted; this year’s baby ice is melting, perhaps, actually faster than last year, despite the evidence of the melt rate, which is really a diminution of ice extent rate.
====================================

57. Gene II
Posted Jul 27, 2008 at 1:23 PM | Permalink

“Expert Says Arctic Ocean Will Soon Be an Open Sea”

Recent news? No

New York Times, February 20, 1969

from article :

“In fact Dr. Budyko (Dr,. Mikhail I. Budyko) argues that an ice-free Arctic Ocean is the “normal” situation.”

58. Gene II
Posted Jul 27, 2008 at 2:11 PM | Permalink

Re # 57

from same New York Times, February 20, 1969 article :

“Col. Joseph O. Fletcher. a retired Air Force polar specialist now with the Rand Corporation in California, has cited the presence or absence of pack ice around Iceland as an index of such trends (i.e. sunspot activity trends). From the 9th century to the 13th century almost no ice was reported there. This was the period of Norse colonization of Iceland and Greenland.”

More evidence of Medieval Warming. Did I just hear a Michael Mann wince?

59. Posted Jul 27, 2008 at 2:26 PM | Permalink

http://freepdfhosting.com/d8ba65962a.pdf

and also lots of other references to limited ice pack dating back to the 9th Cetury in my thread ‘Seaice through the Ages’ I would agree that the norm is for there to be limited Arctic ice which subsequently encouraged a great deal of migration-other than the Vikings-around the lands that fringe the Arctic.

Tony Brown

60. UK John
Posted Jul 27, 2008 at 2:32 PM | Permalink

Phil, (or anyone)

A question about ice melt that I cannot find a reference to.

The Artic melt season of 2007 was very sunny, comparitively little cloud cover. So I thought this would be why the ice melted. This was mentioned on the NSIDC web site by Sereze but seemed to get lost in the “unprecendented ” noise and not followed through.

I tried a few simple experiments of ice floating on water, some in the shade and some in the sun (the same water being circulated around).

The ones in the sun melted much quicker.

So maybe lots of sunshine melts ice quick, not an earth shattering conclusion, but why wasn’t the obvious question of trying to find an explanation for the “unprecedented” lack of clouds followed up.

61. DeWitt Payne
Posted Jul 27, 2008 at 3:26 PM | Permalink

revised data:
date extent(Gm2) difference EWMA difference
7/26/2008 7.525000 -0.082969 -0.085268

Not much change. I think it’s Gm2 (gigameters squared).

The lack of cloud cover was also very probably the reason extent increased so rapidly (unprecedentedly?) in late October and early November 2007 as well.

62. kuhnkat
Posted Jul 27, 2008 at 9:18 PM | Permalink

Phil re#27,

I did not predict anything, just called your numbers funny as they were simply an exercise in extrapolation.

Unless you are just playing games with number projection, as Atmoz and Lucia did on their bet, it is a good idea to take a look at whether the conditions for the period from which you are extrapolating were changing then or now.

63. bender
Posted Jul 27, 2008 at 9:46 PM | Permalink

#62

Unless you are just playing games with number projection, as Atmoz and Lucia did on their bet

Could you provide a link to this bet? I must have missed it. TIA

64. DeWitt Payne
Posted Jul 27, 2008 at 10:10 PM | Permalink

agn,

Oops. That’s correct. This is a leap year so the date is one lower, not one higher, than non leap years.

Day 209, preliminary
date extent(Gm2) difference EWMA difference
7/28/2003 7.777656 -0.083438
7/28/2003 7.922969 -0.080156 -0.073806
7/27/2004 8.250469 -0.098906 -0.064488
7/28/2005 7.497344 -0.061719 -0.082048
7/28/2006 7.469844 -0.080000 -0.060343
7/28/2007 6.688594 -0.092656 -0.095700
7/27/2008 7.472969 -0.052031 -0.081945
No EWMA for 2002, too much missing data.

That’s still only four increasing points in a row. That’s not enough to call, but it’s less likely 2008 will catch 2007. Looks like neck and neck with 2005 and 2006, though.

65. Posted Jul 27, 2008 at 11:18 PM | Permalink

Re #62

Phil re#27,

I did not predict anything, just called your numbers funny as they were simply an exercise in extrapolation.

Unless you are just playing games with number projection, as Atmoz and Lucia did on their bet, it is a good idea to take a look at whether the conditions for the period from which you are extrapolating were changing then or now.

Well if you recall that extrapolation was made in the context of the bet with lucia and Atmoz: http://rankexploits.com/musings/2008/test-post/

It’s hardly a prediction though if you wait to see what happens before you make it, which appears to be the approach you advocate!

66. P. Hager
Posted Jul 27, 2008 at 11:36 PM | Permalink

DeWitt,
re #64

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

only matches part of your data. Your data for 2005, 2006 and 2007 appear to match the data for day 207.
Based on the above refereced data source, the data for day 209 should be:

7/28/2002 no data
7/28/2003 7922969 -80156
7/27/2004 8250469 -98906
7/28/2005 7307031 -79063
7/28/2006 7340000 -61250
7/28/2007 6527969 -66875
7/27/2008 7472969 -52031
Can someone else confirm this?

67. DeWitt Payne
Posted Jul 28, 2008 at 12:32 AM | Permalink

You are correct on 2005-2007, made the same mistake again somehow. But I downloaded again and checked on my spreadsheet and there is data for 7/28/2002 as reported. Next time I’ll copy the whole row with date included.

Day 209, preliminary, corrected *sigh*
date extent(Gm2) difference EWMA difference
7/28/2003 7.777656 -0.083438
7/28/2003 7.922969 -0.080156 -0.073806
7/27/2004 8.250469 -0.098906 -0.064488
7/28/2005 7.307031 -0.079063 -0.083139
7/28/2006 7.340000 -0.066125 -0.062938
7/28/2007 6.527969 -0.066875 -0.092642
7/27/2008 7.472969 -0.052031 -0.081945
No EWMA for 2002, too much missing data.

68. MrPete
Posted Jul 28, 2008 at 6:41 AM | Permalink

DeWitt, looks like your first row is stuck on “2003” but should be “2002”.

Am I reading this correctly, that (at least on day 209) 2002 lost .083 while 2008 lost .052, so 2002 is (today) catching up with 2008 at .031 per day… and thus (if today’s data were to continue) would pass 2008 in ten days or so?

I realize nothing is static, we don’t know what will happen, etc. I’m just wanting to be sure I’m skimming the charts correctly.

69. Luis Dias
Posted Jul 28, 2008 at 7:29 AM | Permalink

#68

There’s too much noise to infer that from one day. Try to get 10 day averages and see what you can find.

70. Posted Jul 28, 2008 at 7:55 AM | Permalink

#60

Evidently summer 2007 in the Arctic was the sunniest since 2002. Whether that coincides with the ‘hottest’ part of the summer I don’t know, as that would be relevant in trying to find comparisons. Being a skier I suspect the science of the sun melting snow and ice quickly is very well known to ski waxers as well as scientists, but how much research there is by the latter group to come up with melt figures I don’t know.

Tony Brown

71. ared
Posted Jul 28, 2008 at 8:55 AM | Permalink

revised results for day 209 are in, melt was even smaller than the prelim figure:

Day 209
date, extend, melt
07-28-2003, 7922969, -80156
07-27-2004, 8250469, -98906
07-28-2005, 7307031, -79063
07-28-2006, 7340000, -61250
07-28-2007, 6527969, -66875
07-27-2008, 7475938, -49062

10-day moving average dropping like a brick, but melt needs to stay this low for the baby ice to have a chance at beating 2006 come September.

72. Posted Jul 28, 2008 at 10:11 AM | Permalink

Now that sea-ice melt out has been completed in Hudson and Baffin Bays the daily sea-ice loss rates should remain between 40,000-65,000sq.km/day for the three or four weeks or so.

73. Jared
Posted Jul 28, 2008 at 1:29 PM | Permalink

Excellent point, Tom, one that some people were missing. The ice in Hudson and Baffin Bays lasted much longer than last year, and their recent rapid melt was a big part of 2008’s big melt days recently. Now that mainly just the Arctic Circle ice remains, and most of the Arctic looks to be cool and cloudy over the next week or so, I expect melt rates to go down for the remainder of the season. 2008 should finish not only easily below 2007, but probably below 2005 and 2006 as well.

74. DeWitt Payne
Posted Jul 28, 2008 at 1:51 PM | Permalink

I’m about ready to stick a fork in catching 2007. The loss rate would have to average over 15,000 km2/day higher than 2007 for the next 61 days to catch up. I don’t see that happening absent some sort of major shift in the weather that causes either consolidation or melting or both. I’m going to start tracking the deficit to 2005 and 2006 now.

75. jeez
Posted Jul 28, 2008 at 1:54 PM | Permalink

I am gratified that other posters have adopted the non-pejorative term baby ice when referencing the temporally challenged.

76. See - owe to Rich
Posted Jul 28, 2008 at 2:20 PM | Permalink

Yeah, “baby ice” is great – it’s not often the sceptics get an emotional one-up on the alarmists.

I’m glad to see that DeWitt Payne has joined my party following 06 and 05, even if 10 days behind the times!

Rich.

77. DeWitt Payne
Posted Jul 28, 2008 at 2:47 PM | Permalink

To catch 2006, the melt rate for 2007 will have to average 2,200 km2/day higher than 2006. To catch 2005, the melt rate will have to average about 2750 km2/day higher. The rate deficit to 2006 was about 8,000 km2/day about 2 weeks ago, so catching up can be done. Looking at the EWMA extent rates for 2005 and 2006 and comparing to 2008, it looks like 2008 will easily catch 2006, but probably won’t catch 2005 as the current rates for 2005 and 2008 are very similar and similar to 2007 as well. See the graph here.

78. crosspatch
Posted Jul 28, 2008 at 7:58 PM | Permalink

Today’s arctic cam shows an air temperature of -0.5 degrees and cloudy conditions. Not a lot of melt going on at the pole today due to surface conditions. I don’t know what the ocean water temperature is under that ice, though.

79. STAFFAN LINDSTROEM
Posted Jul 28, 2008 at 8:47 PM | Permalink

# 78 crosspatch… If you look closely at that little? polyuna
close to the webcam, you’ll see that it is a thin frozen
layer of ice…and some new snow…Other cams on other
occasions often show mackrel clouds CMIIW, these are also
seen here down at 59N in Solna/Stockholm area, more often
I think the latest 18 months or so. So makrels and baby ice
saves the planet …!?

80. Steve McIntyre
Posted Jul 28, 2008 at 8:54 PM | Permalink

For refresher, here’s the script that I use to collate:

url=”http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv”
#AMSR-E sea ice concentration algorism developed by Dr. Comiso in NASA/GSFC.
dim(daily) #[1] 2406 4
names(daily)=c(“month”,”day”,”year”,”ice”)
daily\$ice[daily\$ice== -9999]=NA
daily\$date< -as.Date(paste(daily\$year,daily\$month,daily\$day,sep="-"))
daily\$julian<-julian(daily\$date,start="1970-01-01")
daily\$mm=100*daily\$year+daily\$month
daily\$dd=factor(daily\$year)
m0=tapply(daily\$julian,daily\$year,min)
m0[1]=julian(as.Date("2002-01-01"),start="1970-01-01")
levels(daily\$dd)=m0
daily\$dd=as.numeric(as.character(daily\$dd))
daily\$dd=daily\$julian-daily\$dd+1
daily\$ice=daily\$ice/1E6
daily\$diff=c(NA,diff(daily\$ice))

f=approxfun(daily\$julian,daily\$ice)
daily\$ice=f(daily\$julian)
daily\$diff=c(NA,diff(daily\$ice))

temp=!is.na(daily\$ice); N=max(daily\$julian[temp])-min(daily\$julian)+1
temp=(daily\$dd== daily\$dd[N])
daily[temp,c(1,2,3,4,9)]

81. Steve McIntyre
Posted Jul 28, 2008 at 8:56 PM | Permalink

De Witt, what are EWMA differences?

82. DeWitt Payne
Posted Jul 28, 2008 at 9:14 PM | Permalink

I hope I get it right this time.
Day 210
Missing extent data has been filled by linear interpolation
date extent(Gm2) difference EWMA difference
7/29/2002 7.696289 -0.081367 -0.086226
7/29/2003 7.843750 -0.079219 -0.074441
7/28/2004 8.132031 -0.118438 -0.067930
7/29/2005 7.212656 -0.094375 -0.082731
7/29/2006 7.267656 -0.072344 -0.062769
7/29/2007 6.479375 -0.048594 -0.088237
7/28/2008 7.385938 -0.090000 -0.082483

2008 made up a big chunk on 2006, a small chunk on 2007 and lost ground to 2005.

83. Steve McIntyre
Posted Jul 28, 2008 at 9:24 PM | Permalink

Looking ahead, 2007 has some big days in a couple of days. I can’t see any way that 2008 can catch up; too much time is off the clock. I think that CA can fairly claim to have been on this story well ahead of the forecasts from the sea ice people.

2006 (and 2005) is a race. 2008 has been gaining steadily on 2006 for some time.

84. DeWitt Payne
Posted Jul 28, 2008 at 9:28 PM | Permalink

EWMA is the Exponentially Weighted Moving Average or Exponential Moving Average, in this case with an alpha of 0.1. EWMA(t) of X(t) = alpha * X(t) +(1-alpha)* EWMA(t-1). Or see here about half way down the page. It’s used in industry in control charts to detect small shifts (sigma 0.5 to 2) in a process. The difference data is so noisy that I can’t really tell what’s happening from the raw data. I like EWMA because it gives a lot of weight to the most recent points.

85. jeez
Posted Jul 28, 2008 at 10:09 PM | Permalink

WOO HOO! THE BABY ICE IS GOING HOME!

BABY ICE! BABY ICE! BABY ICE!

86. AndyW
Posted Jul 29, 2008 at 12:08 AM | Permalink

#85 etc Probably does not add any insight to the discussion and perhaps should be reduced to zero or less.

Regards

Andy

87. Luis Dias
Posted Jul 29, 2008 at 2:48 AM | Permalink

#86

Whining probably does not add any insight to the discussion and perhaps should be reduced to zero or less.

Regards

Luis

88. jeez
Posted Jul 29, 2008 at 3:04 AM | Permalink

Heh

89. Posted Jul 29, 2008 at 3:44 AM | Permalink

UK John says:
July 27th, 2008 at 2:32 pm (60)
quote So maybe lots of sunshine melts ice quick, not an earth shattering conclusion, but why wasn’t the obvious question of trying to find an explanation for the “unprecedented” lack of clouds followed up. unquote
Like your comment that ‘it’s getting warmer because it’s getting sunnier’, this is an obvious truism which leaves me, like you, puzzled about the lack of follow-up. I’ve seen one explanation which is weather pattern related: high pressure areas have sinking air which suppresses cloud formation. Maybe the answer is so obvious it’s not worth researching. Having said that, I’d love to skim the top .1mm of the surface.

http://news.bbc.co.uk/1/hi/programmes/newsnight/7521339.stm is a pointer to a blog which sounds like it will be very interesting.

JF

90. tty
Posted Jul 29, 2008 at 5:09 AM | Permalink

I hope the expedition ship is a good icebreaker, otherwise they will be in real trouble this year.

91. John Lang
Posted Jul 29, 2008 at 5:42 AM | Permalink

For those following the North Pole Webcam, note that the webcam and the scientific equipment with it have drifted considerably south, to 84 degrees N in between Svalbard Island and Greenland.

Track is the purple line on this map.

http://psc.apl.washington.edu/northpole/DriftTrackMap.html

92. AndyW
Posted Jul 29, 2008 at 7:10 AM | Permalink

#87 Considering the nature of your post you are skating on very thin ice also.

Regards

Andy

PS apologies for those who hate puns :)

Posted Jul 29, 2008 at 7:47 AM | Permalink

Re: #86

Behave yourself, we’re keeping an eye on you.

-DYFS (Dept. of Youth and Family Services, Baby Ice Division)

94. Posted Jul 29, 2008 at 8:33 AM | Permalink

What’s happening to Antarctic ice situation at this time? Haven’t seen any postings. Maybe I missed them?

95. bender
Posted Jul 29, 2008 at 8:47 AM | Permalink

#85-86 on “baby ice”
humor good

96. DeWitt Payne
Posted Jul 29, 2008 at 8:58 AM | Permalink

Day 210 revised:
7/28/2008 7.390781 -0.085157 -0.081999

A small revision upward, which seems par for the course lately.

Antarctic Ice, at least according to Cryosphere Today, is freezing normally. The Antarctic ice anomaly is close to zero currently. That means the global anomaly is about -1 Gm2, but that is within the normal fluctuation range so there is still no significant trend in global sea ice for the last thirty years.

Steve: Huh? Prelim: 7/28/2008 7.385938 -0.090000 -0.082483 . There’s less melt than the prelim.

97. Douglas Hoyt
Posted Jul 29, 2008 at 9:29 AM | Permalink

Light snow falling in Barrow now and it is predicted to occur again for the next several nights.

98. Luis Dias
Posted Jul 29, 2008 at 10:02 AM | Permalink

#92

Sir, you ought to avoid drowning yourself into puns.

#93

Yes, sir! Right away, sir!

99. Posted Jul 29, 2008 at 10:51 AM | Permalink

Re #97

And it’s 11ºC and sunny at 10 am at Kugluktuk forecast to reach 14ºC this afternoon and 22ºC tomorrow!

Re #96

It’s not a Gm2 if you don’t like km2 it’s Mm2 (in SI the prefix is squared too, if it wasn’t a mm3 would be a litre).

100. Aaron Wells
Posted Jul 29, 2008 at 11:30 AM | Permalink

Steve: Huh? Prelim: 7/28/2008 7.385938 -0.090000 -0.082483 . There’s less melt than the prelim.

Steve, I think that DeWitt was referring to upward revision of the ice extent, not the melt amount.

101. Jedwards
Posted Jul 29, 2008 at 11:52 AM | Permalink

Re #99

And it’s 11ºC and sunny at 10 am at Kugluktuk forecast to reach 14ºC this afternoon and 22ºC tomorrow!

And then projected to turn cold and rainy starting Thursday with the highs falling all the way down to 7ºC by Saturday.

102. Posted Jul 29, 2008 at 1:12 PM | Permalink

Re #101

And then projected to turn cold and rainy starting Thursday with the highs falling all the way down to 7ºC by Saturday.

Actually that’s the low projected to reach 7ºC, looks like good melting weather. ;)

http://www.weatheroffice.gc.ca/city/pages/nu-16_metric_e.html

103. DeWitt Payne
Posted Jul 29, 2008 at 1:56 PM | Permalink

Phil,

Ok, but then how do you get rid of the other six orders of magnitude? MMm2 or Mkm2 seems awkward to me. Let’s work it through as I should have done in the first place. Say you have a square that’s 1,000 km on a side to give an area of 1,000,000 km2. You can also express that as 1 Mm on a side for an area of 1 Mm2 or by the rule of squaring the prefix too that should be Tm2 not Gm2. So I was only off by 3 orders of magnitude. A mere pittance.

I was indeed referring to an upward revision of the extent not the loss in #96.

104. STAFFAN LINDSTROEM
Posted Jul 29, 2008 at 2:50 PM | Permalink

#102 phil. … FYI Kugluktuk may need all the warmth
it can get to reach normal July temps; so far 9.5C or so
according to Weather Underground. July average is 10.7C..
Why didn’t you ring the alarming melting-bell on 17th??
Perhaps the only day this summer over 25C??!! Absolute
record according to Environment Canada is 34.9C from …
no drumroll needed … July 15 … 1989 …Checking
the UIUC site I also find more curious things about
disappearing and reappearing ice in James Bay July-Aug 1989…Hmmm
Steve M, we have’nt even started yet!? How many issues
do we have?? Lift one stone and there are 2 new ones to roll
up the mountain, Sisyphos clone yourself by the thousands!!!

105. DeWitt Payne
Posted Jul 29, 2008 at 3:10 PM | Permalink

From the BIPM:

Compound prefix symbols, that is, prefix symbols formed by the juxtaposition of two or more prefix symbols, are not permitted. This rule also applies to compound prefix names.

So Mkm2 is not permitted in SI units.

and:

The grouping formed by a prefix symbol attached to a unit symbol constitutes a new inseparable unit symbol (forming a multiple or submultiple of the unit concerned) that can be raised to a positive or negative power and that can be combined with other unit symbols to form compound unit symbols.

So officially it’s Mm2 for 1,000,000 km2 as you said. I’ll get this right eventually.

106. UK John
Posted Jul 29, 2008 at 4:17 PM | Permalink

#89 Julian,

My hypothesis is that ice melt is proportional to insolation received during the summer melt months. Clouds reduce the insolation and the melt, no clouds high melt!

All sounds crushingly logical, but I haven’t got the will or knowledge to pursue this, I only know that June 07 and July 07 in the Artic were almost cloud free, so unforgiving sunshine 24 hours a day, no wonder the ice melted.

107. Posted Jul 29, 2008 at 4:26 PM | Permalink

What are we all going to do when winter sets in and the race has finished? We need to start planning now…

Tony Brown

108. gens
Posted Jul 29, 2008 at 4:36 PM | Permalink

With all due respect to Steve’s basketball analogies, this race is more like a limited overs cricket match with the required run rate steadily going up while the overs are counting down. 2008 desperately needs a few high scoring overs full of sixes. (I’m guessing most Americans and Canadians will have no idea what I am talking about).

Steve: I do.

109. Mark T.
Posted Jul 29, 2008 at 4:48 PM | Permalink

None whatsoever.

Mark

110. Gunnar
Posted Jul 29, 2008 at 5:08 PM | Permalink

>> My hypothesis is that ice melt is proportional to insolation received during the summer melt months

Embarrassing counter intuitive voodoo science. Obviously, such an oversimplified idea could not have escaped the razor sharp minds of our great government funded scientific establishment.

111. Posted Jul 29, 2008 at 8:01 PM | Permalink

Re #108

With all due respect to Steve’s basketball analogies, this race is more like a limited overs cricket match with the required run rate steadily going up while the overs are counting down. 2008 desperately needs a few high scoring overs full of sixes. (I’m guessing most Americans and Canadians will have no idea what I am talking about).

Of course limited over matches are frequently won in such a manner (particularly 20/20). ;)

112. Mike Bryant
Posted Jul 29, 2008 at 8:25 PM | Permalink

I know this is off topic but I hope you will find it interesting and important…

Hey Tony, I have an idea. Maybe we can figure out why we still do not have the AIRS CO2 imagery from the satellite that was launched May 2002.

All we have is July 2003.

http://www-airs.jpl.nasa.gov/Products/CarbonDioxide/

Under the image it says January 2003. This is odd since all their other “products” show two images, January and July 2003. Here:

http://airs.jpl.nasa.gov/News/Features/FeaturesNewGlobalMaps/

113. Steve McIntyre
Posted Jul 29, 2008 at 9:08 PM | Permalink

DAy 211
month day year ice diff
7 30 2002 7.614922 -0.08136717
7 30 2003 7.795469 -0.04828100
7 29 2004 8.070625 -0.06140600
7 30 2005 7.123750 -0.08890600
7 30 2006 7.198594 -0.06906200
7 30 2007 6.428125 -0.05125000
7 29 2008 7.316250 -0.07453100

114. DeWitt Payne
Posted Jul 29, 2008 at 9:11 PM | Permalink

Day 211 preliminary
missing extent data interpolated
date extent(Mm2) difference difference(EWMA)
7/30/2002 7.614922 -0.081367 -0.085740
7/30/2003 7.795469 -0.048281 -0.074919
7/29/2004 8.070625 -0.061406 -0.072980
7/30/2005 7.123750 -0.088906 -0.083895
7/30/2006 7.198594 -0.069062 -0.063726
7/30/2007 6.428125 -0.051250 -0.084539
7/29/2008 7.316250 -0.074531 -0.081252

lost a little to 2005 gained on 2006 and 2007(but nowhere near enough).

115. DeWitt Payne
Posted Jul 29, 2008 at 9:26 PM | Permalink

Five points in a row above the smoothed maximum difference. Based on the behavior in past years, we may have seen the inflection point in the difference curve.

116. STAFFAN LINDSTROEM
Posted Jul 29, 2008 at 11:16 PM | Permalink

#110 Gunnar, good to see your posts here in the pack
ice…voodoo science…Lustmord…The reason why the
the ice around the very North Pole refuse to melt is
perhaps the bad angle …well one of the many reasons,
or am I only a amateurish voodoo analyst??!
I want to make a general call for measurements of
ice thickness in the remaining ice 2007 and have
even a nuclear icebreaker succeded reaching the
NP this summer…C’mon Staff it’s early…Well,
nuclear subs then, compare “John Daly’s” 1987 May 18
surfacing with one UK and 2 US subs, January was
even colder than the WW2 Januarys in Sweden and
much of eastern and central Europe…
Unless we get that wonderful satellite that
can measure ice thickness we have’nt really much
of an idea how MUCH ice there is, in contrast
to how LARGE, goes for the Antarctic too, but
if the planetary cooling continues, area/extent
is perhaps quite enough…PS Kugluktuk measured
27C July 17 2008 as Tmax, readings 12-16 above 25C!!
Melt, melt, melt, melt, melt…

117. AndyW
Posted Jul 30, 2008 at 12:04 AM | Permalink

It can be probably said with 100% certainty now the race is between 2008 and 05/06 rather than 2007. Nobody will be swimming to the pole this year, though one or more passages may be open. Although 2008 has been putting up rather big numbers recently whilst 2007 took a breather 2007 is about to go through a 3 or so 100k+ phase which looks unlikely for 2008.

However 2008 is peaking a bit later this year so it will be interesting in the next week or 2.

118. Posted Jul 30, 2008 at 3:04 AM | Permalink

Phil #111

Yes Phil but this situation is more akin to a five day test match rather than 20/20 in which games are rarely won in such a spectacular fashion but is more a war of attrition.

However you prove the point I made in post #107 I shall miss you pouring cold (or is it warm) water on to others over excited observations. I shall miss Jeez yelling ‘Baby Ice! and Staffan saying whatever it is he says. SteveM is morally obliged to set up a counselling service for when this game ends.

I fear Mikes suggestion #112 lacks the gladiatorial element needed. Will tracking the creation of new ice be a possible substitute? I fear not. We need to prepare now as the current end game is almost here…

Tony Brown

119. Sean Egan
Posted Jul 30, 2008 at 3:07 AM | Permalink

STAFFAN LINDSTROEM
The sub data is not that straight forward. It is accurate but only on the track the sub took. The subs are hiding so they do not take the same track at the same time of the year, and the ice is moving too. To combine the tracks requires assumptions. What are the right assumptions are disputed.

What we need is ICESAT which can laser range the lot in days. However, there was manufacturing fault and it’s lasers have a much shorten life. So it is only taking the occasion snapshot. The only 2007 to 2008 comparision I have seen is here http://www.nsidc.org/arcticseaicenews/2008/040708.html
The text suggests there is more young/thin ice this years, which makes sense in a recovery after a big melt year. These guys are really not baby ice fans, and appear to have triggered the big melt in 2008 media hype. So I would really like to see same day snapshots and reach me own conclusion.

120. Posted Jul 30, 2008 at 3:45 AM | Permalink

As I just noted at my blog, the BBC just slipstreamed in a correction to the “2008 is going to be Teh Worst Evah!!” in a report about an ice sheet off Ellesmere Island today. Said article oddly omits to link to the “OMG World Melts” article from 6 weeks ago.

121. bernie
Posted Jul 30, 2008 at 5:08 AM | Permalink

The Globe and Mail has an excellent map of the “collapse” of this ice sheet. Apparently its collapse has been proceeding for about 100 years. GISS has temp data (raw) for Alert and Eureka but the data is fragmentary with the most recent temperatures showing cooler than average temperatures.

122. Sean Egan
Posted Jul 30, 2008 at 6:44 AM | Permalink

Anyone else seen the annoying CNN story on Arctic ice today? Pictures comparing of 1980 to 2008, and the usual claim we heading for a record melt due to thin ice. Annoying as they failed to mention there is more ice today than a year ago. Claims baby ice will melt very rapidly in Sept. No sources indicated to back this up, but I am guessing NSID got a phone call.
There was a lead in story about the break off a junk of ice from Ward Hunt Ice Shelf, north coast of Ellesmere Island. The online version clearly states that “Derek Mueller, a researcher at Trent University, was careful not to blame global warming…” The TV version clearly blame global warming. The main story about the expected melt is not in CNN.com/World at least not at 14:00 CET

123. DeWitt Payne
Posted Jul 30, 2008 at 8:45 AM | Permalink

Rapid ice melting in September, too funny. Late September is when it starts to freeze again. The annual rate plots are all very close at that point. Talk about grasping at straws.

revised extent:

7/29/2008 7.324219 -0.066562 -0.080455

Again a slight upward revision in extent (less loss).

If July 24 is indeed the inflection point, then it falls in the middle of the range for 2002 to 2007. The earliest was 7/4/2007 and the latest 8/10/2004. The maximum loss rates are also quite close except for 2007:

2002 -0.087136
2003 -0.083339
2004 -0.084827
2005 -0.089251
2006 -0.088280
2007 -0.106188
2008 -0.087110 (tentative)

These are the EWMA smoothed rates using an alpha of 0.1.

124. ared
Posted Jul 30, 2008 at 8:50 AM | Permalink

Well, you can’t say the baby ice doesn’t put up a fight to stick with 2006. Revised etxent for day 211 is up 8000 km or so; 2008 now gainig precisely 2500 km on 2006.

month,day,year,extend,melt
7,30,2003,7795469,48281
7,29,2004,8070625,61406
7,30,2005,7123750,88906
7,30,2006,7198594,69062
7,30,2007,6428125,51250
7,29,2008,7324219,66562

125. Posted Jul 30, 2008 at 10:47 AM | Permalink

Re #60

Phil, (or anyone)

A question about ice melt that I cannot find a reference to.

The Artic melt season of 2007 was very sunny, comparitively little cloud cover. So I thought this would be why the ice melted. This was mentioned on the NSIDC web site by Sereze but seemed to get lost in the “unprecendented ” noise and not followed through.

It seems that at least for parts of this summer that it has also been very sunny.

“Towards the end of the flight, the cloud comes down and we duck underneath it until it feels like we are almost touching the sea. Apart from this cloud and the fog that delayed my arrival, I’ve seen clear blue skies all week.
It’s hard to believe that’s not normal. During the summer, the Arctic is, on average, covered in cloud 80% of the time because of all the moisture from the ocean and melt ponds.”

Ice diary: Science in the fast-changing Arctic

126. Posted Jul 30, 2008 at 11:35 AM | Permalink

Re #123

Rapid ice melting in September, too funny. Late September is when it starts to freeze again. The annual rate plots are all very close at that point. Talk about grasping at straws.

That’s fine when you look at the big picture, however when you look at the detail some interesting nuggets emerge. Essentially everywhere except the Laptev and E. siberian seas are at or about last year’s values as I’ve said before, ~0.5 million sq km remain in the ES and ~0.4 million sq km remain in the LS. Last year the ES was all gone by now whereas it normally reaches its minimum by early september, further losses there this year could continue for about 6 weeks. Similarly the LS had just about reached its minimum for the year (~0.1) by now and again the normal time for the end of melting there is early september so potential for further losses exists there too. How close 2008 gets to setting a new record depends on what happens in the ES & LS and the story there is far from over.

127. Sean Egan
Posted Jul 30, 2008 at 12:28 PM | Permalink

CNNs annoying report today appears to be a reheat of http://edition.cnn.com/2008/WORLD/weather/06/27/north.pole.melting/index.html
Although the weather woman presenter on what I assume was “World News” was more firm than in this piece and ice free north pole has become record melt. If she has recontacted Mark Serreze for an update in recent days, he must be a brave man.
DeWitt Payne, I follow you point about Sept. But if you really want to predict a record melt, you have to put your hoped on the refreeze being late or a sudden event at the end, as it aint happening now. Plus you can re-serve the same dish in August. I would not normally comment a TV news item, but CNN has a world audience and reputation like the BBC.

128. DeWitt Payne
Posted Jul 30, 2008 at 3:17 PM | Permalink

Phil,

2007 hit minimum ice extent on 9/24. That’s late compared to the previous 5 years. From the same year day as yesterday it lost an additional 2.173594 Mm2 or an average rate of -0.039520 Mm2/day. In order to catch 2007, 2008 will have to lose 3.069688 Mm2 or a rate of -0.055813 Mm2/day assuming the minimum is 9/23/2008 or about 8 weeks from now. That’s over 40% faster than 2007. The present EWMA loss rate for 2008 is -0.080455 Mm2/day compared to -0.084538 in 2007 (which will increase to -0.088748 Mm2 by 8/5). Melting ice takes energy and average insolation is decreasing rapidly. The increased albedo from the larger 2008 ice extent would seem to make faster melting than 2007 unlikely. Even if you assume the melt rate is in some way proportional to ice extent, which isn’t shown by the data, 2008 has only 14% more ice than 2007 as of yesterday.

I still can’t say with 100% confidence that 2008 won’t have the same or lower minimum ice extent than 2007, but I would say I’m 90 to 95% confident that it won’t. I expect the additional loss for 2008 will be very close to the same as for 2007. That would make minimum extent for 2008 5.15 Mm2. That would be the second lowest extent in the last seven years by 0.16 Mm2 but still 0.9 Mm2 higher than 2007. The odds are still close to even that it will be the third lowest, not the second (it won’t catch 2005). 2005 lost 1.81 Mm2 from yesterday to it’s minimum on 9/21/2005.

So what was the state of the LS and ES at this time in 2005? That’s the year that looks most like 2008 at this point.

129. AnInquirer
Posted Jul 30, 2008 at 3:19 PM | Permalink

Although many of us are hooked on the day-by-day ice melt and this blog’s conversation about it, perhaps it would be helpful to read what is being said by full-time researchers who study the ice every day:

http://nsidc.org/arcticseaicenews/index.html

Just to prevent any possible surprise, this website is from a pro-AGW organization.

130. UK John
Posted Jul 30, 2008 at 4:38 PM | Permalink

#129

We all read the expert researchers view, and this Blog started off (it seems like an age ago) by Steve saying what the experts nearly all said “that 2008 will be lower than 2007″ and then wondering how the expert forecasts would turn out.

At the moment, it appears, the average blogger’s forecast is just as good as the experts. An expert is an expert until he proves he gets it wrong, then is he an expert any more ???

Another analagy is if you want to know why the Trains run late, you could ask the railway company, but you might just get told the company line, to really find out, just ask a trainspotter, he will tell you exactly what’s going on! This Blog is made by Trainspotters, and its doing OK.

Posted Jul 30, 2008 at 4:47 PM | Permalink

Question: Why is 1979 used as the datum? Is it because that is the first year adequate records are available for this project? Or is it because 1979 was a peak year for retained ice cover, and limitation to 1979 thereby tweaks the stats ‘n’ graphs in a manner that increases the perception of recent abnormal melting? Something else?

132. Steve B
Posted Jul 30, 2008 at 5:18 PM | Permalink

Question: Why is 1979 used as the datum? Is it because that is the first year adequate records are available for this project? Or is it because 1979 was a peak year for retained ice cover, and limitation to 1979 thereby tweaks the stats ‘n’ graphs in a manner that increases the perception of recent abnormal melting? Something else?

Satellite coverage began in 1979 which established a benchmark.

133. bender
Posted Jul 30, 2008 at 5:18 PM | Permalink

I still can’t say with 100% confidence that 2008 won’t have the same or lower minimum ice extent than 2007, but I would say I’m 90 to 95% confident that it won’t.

You could do better than that. You could estimate the standard error on your daily ice melt measures and build a confidence interval around your projection. That way you could determine on any given day how confident you are that the 2007 level will not be reached. Your confidence will increase over time as long as the daily melt rate in 2008 does not exceed that of 2007. And drop if the rates are the other way around.

134. BarryW
Posted Jul 30, 2008 at 5:21 PM | Permalink

Re #128

If 2008 does not exceed 2007 the prognostications will quickly be forgotten and replaced with 2007 being the second or third lowest ect. Similar to the way the temperature flattening is ignored and the next year is touted as being in the top 5, top ten and so on. Of course if you hit a peak or trough the values around it will be similar, but that seems to escape the alarmists.

135. STAFFAN LINDSTROEM
Posted Jul 30, 2008 at 5:22 PM | Permalink

#130 UK John…Thank you…High and due time somebody upgraded
us to … Climatespotters??, mostly working from our arm-chairs
but … I’ve been north of the Arctic or Polar Circle in mid
from US including HI…!! Yes, I am/was also a DX-nerd…I confess

136. D. Patterson
Posted Jul 30, 2008 at 6:13 PM | Permalink

BarryW says:

July 30th, 2008 at 5:21 pm
Re #128

If 2008 does not exceed 2007 the prognostications will quickly be forgotten and replaced with 2007 being the second or third lowest ect. Similar to the way the temperature flattening is ignored and the next year is touted as being in the top 5, top ten and so on. Of course if you hit a peak or trough the values around it will be similar, but that seems to escape the alarmists.

It’s more of a case of alarmists fleeing and escaping the values….

137. Gene II
Posted Jul 30, 2008 at 6:16 PM | Permalink

Re #135

I agree there will be a rush to damage control for those who are pessimists/alarmists. You only have to look at how the temperature spike of 1998 has been handled by the pessimists/alarmists to find some evidence for why I say they will do this. For them 1998 used to be more alarming proof that man is causing the earth to warm. But now, because no year since 1998 has been warmer than 1998 [unless you believe James Hansen ;)], they say 1998 was only an el Nino anomaly and without it an upward “trend” in temps can be seen [at least until the end of 2006 ;)]. They spin and spin. With all this dizzying spinning they’ve become disoriented–and that would explain why they still think the Hockey Stick is good science ;).

138. Jeff K
Posted Jul 30, 2008 at 6:23 PM | Permalink

From earlier talk about sunshine melting the polar ice – I guess that would be true…to a degree (pun intended). I would guess, as long as the air temperature is around 29-30 F or higher, the solar insolation would overpower the air temperature and allow surface melting. *However*…at those latitudes & sun angle, what would the air temp have to be to keep the surface ice below freezing even in full sun?

139. DeWitt Payne
Posted Jul 30, 2008 at 6:28 PM | Permalink

You could estimate the standard error on your daily ice melt measures and build a confidence interval around your projection.

Well, yes, if I knew what I was doing and not just mostly flapping my arms real hard. Right now I can’t even calculate control limits for an EWMA chart.

Here’s what I have: daily smoothed rates for 2002 to current date. I’ve averaged the rates for 2002 to 2007 for each day from 7/1 to 10/31. I’ve calculated the total loss from yesterday to minimum extent for each year, averaged and calculated s.d. I could also calculate the s.d. for each day but haven’t yet. So what I want is a projected minimum extent each day with a confidence interval that shrinks as the number of days to minimum extent gets smaller. Would it work if I used a t statistic for 95% confidence on the standard deviation of the loss to minimum? Now I have to go find a handbook or my undergraduate stat book for a t table. First a crude underestimate using +/- 2 s.d.:

Projected minimum = 5.38 Mm2
Projected upper limit = 5.99 Mm2
Projected lower limit = 4.77 Mm2
2007 minimum = 4.26 Mm2 or outside the current range
2003 minimum = 6.03 Mm2 also outside current range

Here’s a graph of the 2008 rate compared to the 2002 to 2007 average daily rate. Not much apparent difference. I could also subtract the average value from 2008 value and plot it on an individuals control chart using the July data to calculate control limits. That probably won’t work, though, because the individual values aren’t(?) independent.

140. DeWitt Payne
Posted Jul 30, 2008 at 7:16 PM | Permalink

Small math error calculating delta to minimum extent for one year.

Upper Limit 6.05 Mm2
Expected 5.42
Lower Limit 4.80
so 2003 not out of range yet.

141. DeWitt Payne
Posted Jul 30, 2008 at 7:44 PM | Permalink

If I read the t table correctly, 6 data points so 5 degrees of freedom, 2x is close enough for 90% confidence and +/-2.571*s.d. gives the 95% limit. The lower limit for 95% confidence is 4.62 Mm2 so I can reject the hypothesis that 2008 will catch 2007 at the 95% level. Show me any data that proves that a loss of 3 mM2 of extent in the ~8 weeks remaining to minimum ice extent is possible. I’m tired of all the speculation about the effect of thin or broken ice or the lack of old ice.

142. Gerald Machnee
Posted Jul 30, 2008 at 7:57 PM | Permalink

It was against my better judgment but I “peeked”. Someone at RC asked how long can you not go beloe the minimum of 2007 and still be trending to an ice free Arctic. The reply was 5 years – sort of similar to not being warmer than 1998. They are much more optimistic about this year than the comments here.
Their 2007 thread is somewhat humorous with forecasts for an ice free Arctic in 2011 and 2012. Enough said. Great posts here! I will be good now.

143. Posted Jul 30, 2008 at 8:37 PM | Permalink

Re #128

So what was the state of the LS and ES at this time in 2005? That’s the year that looks most like 2008 at this point.

DeWitt, 05 had significantly more losses in the ES & LS at this stage than this year.

Cf 05 & 08

144. DeWitt Payne
Posted Jul 30, 2008 at 9:14 PM | Permalink

I went back and calculated the data from June 20 (the earliest data point for 2002) on. Here’s the graph. The y axis is km2 not Mm2. The interesting thing to me is that the projected minimum has hardly varied in all that time while the extent has gone from 10.4 Mm2 to 7.3 Mm2. The average of all the projected extents is 5.48 Mm2 with a s.d. of 0.039. That’s between 2002 at 5.65 Mm2 and 2005 at 5.32 Mm2. The least squares trend line of the daily projections has a negative slope of -0.001290 Mm2/day (R2=0.15). The 95% confidence lower limit exceeded the 2007 minimum extent on July 10.

7/30/2008
Upper Limit Projected Lower Limit (95% confidence)
6.23 Mm2 5.43 Mm2 4.62 Mm2

Only the 2007 minimum can be rejected at the 95% confidence level.

145. Steve McIntyre
Posted Jul 30, 2008 at 9:17 PM | Permalink

Day 212 – middle of the pack. Melt rates definitely seem to be on the decline. August starts getting cool at night even in southern Canada.

month day year ice diff
7 31 2002 7.534 -0.08137
7 31 2003 7.732 -0.06359
7 30 2004 8.013 -0.05719
7 31 2005 7.046 -0.07781
7 31 2006 7.143 -0.05531
7 31 2007 6.375 -0.05281
7 30 2008 7.264 -0.06016

146. Steve McIntyre
Posted Jul 30, 2008 at 9:28 PM | Permalink

For anyone who thinks that September melts “matter” – sometime in the next 23-30 days, we will see the first day with melt under 10,000 sq km (-0.01 in the above tables). After that, about 200-300,000 sq km total melt seems to occur, but you’re dealing with very limited space for 2008 to gain on any other year. As we observed a while ago, the fork is in 2007, but the race with 2006 looks like it will be close right to the end. My guess is that 2002 and 2005 are out of range both ways, but just a guess.

147. Aaron Wells
Posted Jul 30, 2008 at 9:51 PM | Permalink

Here are the raw (non-smoothed) Daily Melt rate graphs for 08 and 07:

Daily Melt Amounts Day 212

As Steve mentioned, daily melt rates appear to be clearly on the decline.

Here is a tracking of 08, 07, 05 and avg-03-06 ice extents:

Daily Ice Extents Day 212

148. DeWitt Payne
Posted Jul 30, 2008 at 10:19 PM | Permalink

Doing a linear extrapolation of the 95% confidence limits for the minimum ice extent, it looks like I will be able to reject all other years on about August 25. At that point the expected additional melt is 0.4 Mm2. That’s also about a month before the expected start of ice extent increase.

149. BarryW
Posted Jul 30, 2008 at 10:34 PM | Permalink

Re #147

except for that whopping melt at about day 180 it looks like 2007 melt pattern tracks fairly closely with most of the others. Low maybe but still with the pack. Still have to see whether the “new ice” theory holds any water.

150. Posted Jul 30, 2008 at 11:07 PM | Permalink

Re #146

An interesting point is that the melt rate is staying fairly constant at ~100,000 sq km/day while the extent is decreasing at a slower rate consequently the average concentration is dropping, now ~72%. It finished up at ~68% last year.

151. DeWitt Payne
Posted Jul 30, 2008 at 11:25 PM | Permalink

I plotted 2007 the same way I’m plotting 2008. It looks very different. The projected value dropped fairly steadily, more rapidly in July, less rapidly in August. But as late as September 5 it was still dropping and hadn’t reached a final value. From late August, the expected loss to minimum was 0.4 Mm2. The actual loss was 0.6 Mm2. At that point, the projection was already well below any previous year at about 4.5 Mm2. The final minimum was 4.26 Mm2. So there is room for loss of extent in late August through mid September, but not much. Here’s the graph.

152. Posted Jul 31, 2008 at 1:19 AM | Permalink

#138

My observations from ski-ing, where digital thermometer displays on public buildings allow some sort of rough estimate, I would say I have seen substantial melting of snow and packed ice at temp as low as 20F.
The rate of melting depends on strength of sun -ie time of year
The inclination of sun-time of year
The inclination of any slope the sun is shining on
Whether part of the slope is in shadow-a tree throws massive shade similarly ice ridges could do the same.
Cloud cover conditions

If all those conditions are favourable however to non melting conditions the temperature can be two or three degrees above freezing without any discernible signs of melting.
I am of course willing to do much more intensive research next winter at various scientifically chosen locations which might just coincide with certain ski resorts.

Tony Brown

153. STAFFAN LINDSTROEM
Posted Jul 31, 2008 at 3:18 AM | Permalink

#150 …phil. 69000 sq kms are VERY approximately
100000 sq kms , I totally agree…
#151 Tony B…ice ridges…Was just going to post
about that. If you look at the AQUA satellite pics,
north of Ellesmere Island,you can see a lot of shadows
OR am I misinterpreting this??, one of the reasons the
baby ice in between? doesn’t melt that fast, or??
About the NP sunniness: Since July 16 only 16 and today
31 if I interprete NOAA’s fisheye cam not too erroneously have been
clear days almost all through,of course 31 isn’t finished yet…. The light snowfalls make
the sunny pics really winterlike, so far so good there
on 85N or so …

154. MrPete
Posted Jul 31, 2008 at 6:06 AM | Permalink

DeWitt, interesting way to visualize the process!

155. Posted Jul 31, 2008 at 6:13 AM | Permalink

Re #153

#150 …phil. 69000 sq kms are VERY approximately
100000 sq kms , I totally agree…

Not sure where you get 69000 from yesterday was ~97000?

156. Gunnar
Posted Jul 31, 2008 at 6:52 AM | Permalink

>> *However*…at those latitudes & sun angle, what would the air temp have to be to keep the surface ice below freezing even in full sun?

In addition to the good points raised by a fellow skier in #152, I’d like to make a few additional points:

1) The north pole in the summer has a very favorable angle.

2) Temp data is a bit of a myth. As T Vonk points out, ice crystals don’t care about our average data, only the specific local temperature. There is a difference between some temp measurement at a different location, at so many feet above the ground, and the location of ice crystals

3) We purposely measure temperature in the shade, not for accuracy, but for consistency. The real air temperature is warmer in the sunshine. Also, the sun will directly heat the ice, while the clear air remains cool.

4) Humidity makes a big difference. In Utah, a lot of snow evaporates in the spring, it does not “melt”. I believe that the arctic north is a tundra, ie desert as well.

5) Ice in water is often more affected by what’s happening with the water, than with the air.

Conclusion: melting ice is not a good indication of the average global air temperature, and therefore of AGW.

157. Posted Jul 31, 2008 at 8:51 AM | Permalink

#156

Thanks Gunnar-fellow skier. I agree with all your points but am sure you agree that more top level research is urgently needed at various scientific stations (AKA known as Ski resorts) This could be CA’s first scientific expedition (although I am perhaps stretching the use of the word scientific!)

One more serious point is about the depth and type of snow, which due to its insulating qualities affects the amount of freezing in the first place but then helps to prevent the thawing. This interesting extract from the link indicated illustrates this;

“The insulating effect of snow reduces
the rate at which seawater freezes to the bottom of the
ice, whereas the high albedo of snow reduces the rate
of ice melting at the top in summer; the resulting dependence
of ice thickness and salinity profiles on the
snow thickness is therefore complex (Maykut and Untersteiner
1971; Ledley 1991). When the snow melts, it
becomes an input of freshwater that affects the salinity
and density structure of the ocean. For all these reasons,
a climatology of snow accumulation, including its geographical,
seasonal, and interannual variations, is needed
for climatic analyses and climate modeling.”

http://www.atmos.washington.edu/~sgw/PAPERS/1999_Arctic_snow.pdf

Tony Brown

158. Aaron Wells
Posted Jul 31, 2008 at 8:57 AM | Permalink

Not sure where you get 69000 from yesterday was ~97000?

Phil, where are you getting your numbers? Here are the melts for the past 7 days (reductions in ice extent area):

93126
71251
82970
49063
85158
66563
53907

Hardly approximating 100k.

159. Aaron Wells
Posted Jul 31, 2008 at 9:07 AM | Permalink

An interesting point is that the melt rate is staying fairly constant at ~100,000 sq km/day while the extent is decreasing at a slower rate consequently the average concentration is dropping, now ~72%. It finished up at ~68% last year.

Phil, I have been equating sea ice extent area reductions to daily melts (ignoring concentration). Are you finding actual melt amounts and average concentrations somewhere?

Here is the revised extent area reductions (I have cut off the early part of the season and start now with day 164 since 2007 and 2008 areas were the same on that day):

Sea Ice Melt Rate Day 212 (revised)

160. STAFFAN LINDSTROEM
Posted Jul 31, 2008 at 9:39 AM | Permalink

#155 phil. … please show us how you got 97.000 sq kms!?

TIME FOR THURSDAY MID-WEEK LAST 7 DAYS ARCTIC ICE MELTING
RECAPITULATION: IN KM2 X 1000 …AND DIFF IN 1000 KM2
23 … 7.772
24 … 7.679 … 93.000
25 … 7.608 … 71.000
26 … 7.525 … 83.000
27 … 7.473 … 52.000
28 … 7.391 … 82.000
29 … 7.324 … 67.000
30 … 7.264 … 60.000

OK phil 69.000 was cherry-picking to get under 70.000 km2,
I admit that…72.500 though is in MY universe VERY etc …
Are you planning a trip with the sailing boat through
the NW passage I’ll give you the “Nordic Serreze’s Number”
25 percent for a week open water in early September.
…”Remember in November the days of September”…

161. Posted Jul 31, 2008 at 9:46 AM | Permalink

Re #158

Aaron as should be apparent from my post (#150) I was not talking about extent, the ice area is dropping by ~100,000 sq km/day.
Extent isn’t a very good indicator of melt when you have the surface covered with a patchwork of floes.

See here for example

162. John Lang
Posted Jul 31, 2008 at 9:50 AM | Permalink

Regarding Phil’s 100,000; I’ve noticed that the warmers are not particularly good with numbers. They are not approaching global warming from a mathematical/factual perspective, but from an emotional “save the planet” perspective.

This, of course, leads to much exageration and dismissal of basic numerical/factual data.

For an example of what I’m talking about, just look at the graph of temperature increases over the past 128 years.

People have an emotional response to GISS’s graph; almost an “oh My God”. But looking at the basic numbers behind it and the actual climate sensitivity implied in it, one should really conclude “Yes, it is warming; but these numbers indicate there is not a significant problem here. It really should be twice as high for us to put significant resources into addressing it.”

163. Posted Jul 31, 2008 at 9:53 AM | Permalink

Re #160

According to the uni-bremen images you’d probably get through the inner passage now.

164. Aaron Wells
Posted Jul 31, 2008 at 10:01 AM | Permalink

Aaron as should be apparent from my post (#150) I was not talking about extent, the ice area is dropping by ~100,000 sq km/day.
Extent isn’t a very good indicator of melt when you have the surface covered with a patchwork of floes.

Phil, that is the impression that I got and that is why I posed the questions to you in #159. Where do find actual ice melt values and average concentrations?

165. Posted Jul 31, 2008 at 10:12 AM | Permalink

Re #162

Regarding Phil’s 100,000; I’ve noticed that the warmers are not particularly good with numbers. They are not approaching global warming from a mathematical/factual perspective, but from an emotional “save the planet” perspective.

This, of course, leads to much exageration and dismissal of basic numerical/factual data.

Well I don’t know who you think is distorting the numbers but it ain’t me!
Basic numerical data: yesterday’s area 5.337 million sq km, today’s area 5.238 million sq km that’s a difference of 99,000 sq km by my math.

166. Aaron Wells
Posted Jul 31, 2008 at 10:22 AM | Permalink

Basic numerical data: yesterday’s area 5.337 million sq km, today’s area 5.238 million sq km that’s a difference of 99,000 sq km by my math.

Phil, I’m begging you… please tell us where you get this ice area data. And you might want to explain why you all of a sudden switched to ice area instead of ice extent when for 500 posts in 2 threads everyone has been discussing ice extent. It might have avoided a lot of confusion if you had been more clear that you were changing the topic to ice area instead of extent.

167. STAFFAN LINDSTROEM
Posted Jul 31, 2008 at 10:31 AM | Permalink

http://www.subpirates.com/viewtopic.php?f=5&t=1710

Have a look on the real ice- and submarine spotters/experts…

AND phil. I of course knew you were counting area, not extent. That
has some advantages but can you show the last week’s area melting,
be my guest… But in the first place: Last year’s minimum extent
was 4.26 million sq kms , and dito area??

168. STAFFAN LINDSTROEM
Posted Jul 31, 2008 at 10:38 AM | Permalink

1. Google “USS 666 Hawkbill” no 10 first page “subpirates”, click!
Have a look on the real ice- and submarine spotters/experts…

AND phil. I of course knew you were counting area, not extent.I just
wanted to see it confirmed… That
has some advantages but can you show the last week’s area melting,
be my guest… But in the first place: Last year’s minimum extent
was 4.26 million sq kms , and dito area??
PS When was the Greenland pic from and where??

169. STAFFAN LINDSTROEM
Posted Jul 31, 2008 at 10:44 AM | Permalink

#168 Sorry for partly doubling the post, took a while…
Triggerhappy Staffan …

170. Posted Jul 31, 2008 at 11:33 AM | Permalink

Re #166

Aaron as I have said multiple times in this thread and its predecessor that the area data comes from Cryosphere Today.
As to your second question I can’t answer it because it’s based on a false premise!
In the previous thread to this one you must have missed inter alia the following:
34, 122, 128, 133, 134, 184, 186, 189, 192, 223, 235, 282, 290, 291, 292, 303, 304, 305, 310, 321, 322, 323, 329, 330, 338, 419.
Try 338 in particular.
I’m sorry that you’re unable to follow things, try reading a bit more carefully, how can you be confused by the following given the rest of the threads:

the melt rate is staying fairly constant at ~100,000 sq km/day while the extent is decreasing at a slower rate

As has been discussed above the extent depends on wind, current and melting, it is not just melting unlike the area, although many posters refer to the change in extent as melt rate that doesn’t make it so.

171. DeWitt Payne
Posted Jul 31, 2008 at 11:48 AM | Permalink

I’ve now plotted 2002 to 2006. The confidence limits stop converging at some point because the dates of minimum extent are different each year so the variability stops decreasing as the date approaches the first minimum extent date, 9/9/2002. This also increases the error in the projection if the actual minimum is significantly different than the average minimum. If one used day before minimum extent, this problem would go away. Unfortunately, we don’t know in advance when 2008 will reach it’s minimum so plotting by calendar date is the only option. I’m now of the opinion that we won’t be able to call the race against 2002 and 2006 on the high end and 2005 on the low end until the actual finish using projected extent. We might, however, be able to calculate a projected minimum date based on rate data. I’ll work on that.

172. Posted Jul 31, 2008 at 11:49 AM | Permalink

Re #168

Last year’s minimum extent
was 4.26 million sq kms , and dito area??

2.96 as I recall, it was ~4.0 on Aug 9th.

When was the Greenland pic from and where??

http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A082101525

Dated 7/28 I cropped the part from the Baffin Sea (bottom center).

173. DeWitt Payne
Posted Jul 31, 2008 at 11:53 AM | Permalink

Phil,

I agree that the use of melt rate to refer to loss of extent is incorrect. I try to avoid it but don’t always succeed. However, melt rate to refer to loss of area isn’t entirely correct either. You can lose area without melting if the wind and currents cause the ice to pile up. Conversely, you can lose ice thickness with no loss in area.

174. See - owe to Rich
Posted Jul 31, 2008 at 12:04 PM | Permalink

#166 Aaron

I had this conversation with Phil a few weeks ago, and he quoted this. However, he still does not realize, or does not admit, that this data is about 7 days out of date, as evidenced by comparison with the Cryosphere Today main graphs. However, that does not really matter, because the gradient is currently fairly constant (by eye), so 100000 km^2 of areal melt seems fair. Therefore, as Phil says, you can calculate that the concentration for the extent is decreasing (where extent is I believe defined as >15% concentration). In fact, for a given reduction in extent at fixed concentration, the areal reduction should be that much _smaller_.

Still, what does that have to do with the price of fish? I suppose, fish spawning and sea temperatures etc, it might have quite a lot to do with it – need a new thread!

Anyway, I’d like to follow area not extent, but the data isn’t as immediately accessible, so extent is the game here, and we’re all enjoying it (though I’m not going to be as distraught as Tony when it’s over :-)).

Rich.

175. Aaron Wells
Posted Jul 31, 2008 at 12:21 PM | Permalink

Aaron as I have said multiple times in this thread and its predecessor that the area data comes from Cryosphere Today.

Phil, I have been visiting CT multiple times a day for several years. I have gone back there again just since your post #170, looking for any sign of a current ice area value. All I can find are graphs. All of the links I can find to datasets are for older data.

One more time. Please tell us where you get this ice area data. If it is from CT, then please tell us how to find it there, because I can’t. If you are getting the data off of a graph, how are you getting it to 3 decimal places?

And I fully understand the differences between “ice extent area” and “ice area” and the factors involved, and the appropriateness of area vs extent. But this thread was started by Steve based upon IARC/JAXA sea ice extent values, and every daily update is sea ice extent. I’ll admit that the term “ice melt” has been used somewhat wrecklessly in place of ice extent area reduction, but that is really what this thread is about, and I for one will continue to discuss ice extent area.

176. UK John
Posted Jul 31, 2008 at 12:22 PM | Permalink

The game here is extent not area. The Game rules were chosen by the “ice science community” who have decide to analyse and benchmark and trend extent.

I did write to David Parker at the UK Hadley Centre wanting to know why they always reported extent and not area, and in short his reply was they had to pick something, neither extent or area are absolute, they both have definitions, but they reasoned that extent would be better for the purpose of trying to find out what was happening in terms of climate change.

Now for irony, what I thought was particularly ironic is when last October the IPCC positioned the UN President on the Antartic Peninsula to make a declaration warning of Global Warming, just at that exact time the sea ice area in Antartica reached an unprecedented recorded maximum.

Steve: I’d be happy to report both. But for daily data, I’ve only been able to locate the series that I’ve been reporting. NSIDC reports binary data which underlies the aggregates, but I haven’t been able to reconcile this data to any daily reporting figures so far. The distinction between “Area” and :extent” may well be relevant, but until I can replicate a calculation, I’m reluctant to throw my own calculation into the fray and would prefer to simply report the JAXA numbers.

177. Steve McIntyre
Posted Jul 31, 2008 at 12:37 PM | Permalink

#175. Phil, let me add my voice to this as well. If you know how to get the daily area data on any method other than your cell phone, give me a URL and I’ll report it and others can look it up. Providing exact data provenance so that others can look it up is a touchstone for this blog. If NSIDC has become so promotional that this data is only available on cell phone, then that’s worth knowing too.

178. DeWitt Payne
Posted Jul 31, 2008 at 12:39 PM | Permalink

To restate again: The reason we’re all concentrating on sea ice extent rather than area is that the daily sea ice extent from 6/21/2002 on is available as a .csv file. There is no equivalent digital data set available, AFAIK, for sea ice area. All we have is the graphical representations on Cryosphere Today and the current day’s data in iphone format. I would do the same analysis on ice area as I’ve done for ice extent in a heartbeat. Why CT doesn’t make this data available is beyond me. And don’t tell me I should ask William Chapman. I shouldn’t have to.

179. Aaron Wells
Posted Jul 31, 2008 at 12:58 PM | Permalink

It appears that if you click on the I-Touch/I-Phone graphic at the CT site, you can see a graphic that lists what is apparently the current ice area. I was not aware of this feature (not owning an I-Touch or I-Phone).

180. See - owe to Rich
Posted Jul 31, 2008 at 1:26 PM | Permalink

Except that, Aaron, as I said in #174 it is either not current or it is not accurate, assuming that the main CT graphs are accurate – just compare the values.

Rich.

181. Steve McIntyre
Posted Jul 31, 2008 at 1:27 PM | Permalink

#179. Isn’t it absurd that this data is available on iPhone and not as an organized digital file for statistical analysis? The entire field occasionally seems to have taken leave of their senses.

182. Jim Arndt
Posted Jul 31, 2008 at 2:09 PM | Permalink

Here is a nice graphic and you can go to any day and compare sea ice.

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

183. John Lang
Posted Jul 31, 2008 at 2:16 PM | Permalink

I will amend my post above that the warmers are not good with numbers.

I will now also add they are not good with making those numbers available to the public since the public should be fed with emotional reactions rather than data and factual information.

How can they produce these maps day after day and not have one single simple acessible database with the figures included?

184. UK John
Posted Jul 31, 2008 at 2:42 PM | Permalink

The reason they picked extent and not sea ice area to Trend is probably that they wanted a metric that suited both North and South poles.

If you think about it extent (as it is defined) probably is the best for one pole that has a large non moving land mass, and one pole where the sea ice has a bit of a swim.

Also when extent was picked about 10 years ago, the whole focus was on sea ice loss and warming in Antartica, not the Artic.

Only a few years later the whole focus has changed, but the metric hasn’t.

185. BarryW
Posted Jul 31, 2008 at 2:49 PM | Permalink

I’d give them some slack in regards to on-line data. Their community is probably insular and is not used to the scrutiny that it has been receiving. They assume that laymen only want to see pretty graphics. Half the time the web-sites and data management are done by summer hires or grad students that took a few computer courses. Doesn’t mean they shouldn’t do the right things, but it takes time for the ship to change course, especially when they know that the people looking at the data are going to be critiquing all of their pronouncements.

186. DeWitt Payne
Posted Jul 31, 2008 at 2:58 PM | Permalink

UK John:

Who’s they? JAXA? Certainly not CT because they plot area not extent.

Eyeballing the graphic on CT, it looks like they are, as usual, about a week behind. That’s assuming CT does the logical thing and uses the first day of the month for the location of the monthly tick mark.

Phil,

Quoting one day’s loss of area is also not very meaningful unless you have the data to show if it’s unusual for the time of year. Given the flatness of the anomaly plot for most of the month of July, I would say it isn’t unusual. At this same time last year, the anomaly was about -2 Mm2 compared to the current -1.3. That projects to a minimum of about 3.7 compared to about 3.0 in 2007 and about 4 to 4.3 for 2002 to 2006.

187. UK John
Posted Jul 31, 2008 at 4:00 PM | Permalink

Phil has been Phil and he has distracted us, this Blog is about extent.

Back to the numbers.

188. Jared
Posted Jul 31, 2008 at 4:50 PM | Permalink

Phil, and others who were rooting for 2008 to overtake 2007, have switched away from ice extent because they know a losing battle when they see one. Banking on ice extent being lower and proving something about AGW? Not working out for you? No problem…just change tactics.

189. Dave Maycock
Posted Jul 31, 2008 at 5:04 PM | Permalink

My apologies for interrupting the flow of such learned people. However, I really must make one point in order to sleep tonight. I will state that I am not a scientist. I am a mechanic with 25 years of experience. I am by nature a very pragmatic person. I am quite confident that should any of you appear in my shop I would be able to tell you with a large degree of certainty what is wrong with the machine you have presented with. I base this outrageous claim on my experience, and the fact that I am very good at what I do. I will not, however, make a claim that I will fix your machine, nor that I am absolutely correct in my diagnosis. To do so would not only be dishonest, but also lead to the loss of my trade and reputation. My reputation is after all, all I have when it comes to not only attracting new customers, but keeping the many I have. There are two ways of dealing with a missed diagnosis when it comes to mechanical repairs; I could try and spin a yarn that follows my original (mistaken) call and hope that I can weave the cost into the bill, or I can admit my mistake and take the financial hit. My experience shows that the latter is by far the only way to proceed if I expect anyone to listen to me ever again. The former tends to lead down a convoluted path that simply makes me look foolish and completely unreliable. This is simply the way it is if one hopes to be respected in ones field.

Why is it that certain folks that represent themselves as experts can be so wrong and yet expect to be listened to as they spin in the wind? I just hope these individuals (who seem to post more than anyone else) realize just how transparent they are to the great unwashed such as myself.

The end of this farce is near. Reality tends to out itself no matter how hard we try and twist it. Remember that this is far more than an exercise in scientific debate. Peoples lives are being affected. Better hope you are on the right end of this thing because pain makes for a good memory.

Many thanks for this exceptional blog. Go baby ice!

190. jeez
Posted Jul 31, 2008 at 6:23 PM | Permalink

Stick a fork in 2008!

191. Aaron Wells
Posted Jul 31, 2008 at 7:25 PM | Permalink

Off-topic, but since Dr. Roger Pielke Sr. posts here, I wonder does anybody know what the deal is with his web site?

Climate Science

It hasn’t worked in about a week.

192. Eggplant fan
Posted Jul 31, 2008 at 7:29 PM | Permalink
193. jae
Posted Jul 31, 2008 at 7:47 PM | Permalink

Dave Maycock, 189:

I will not, however, make a claim that I will fix your machine, nor that I am absolutely correct in my diagnosis. To do so would not only be dishonest, but also lead to the loss of my trade and reputation. My reputation is after all, all I have when it comes to not only attracting new customers, but keeping the many I have. There are two ways of dealing with a missed diagnosis when it comes to mechanical repairs; I could try and spin a yarn that follows my original (mistaken) call and hope that I can weave the cost into the bill, or I can admit my mistake and take the financial hit. My experience shows that the latter is by far the only way to proceed if I expect anyone to listen to me ever again. The former tends to lead down a convoluted path that simply makes me look foolish and completely unreliable. This is simply the way it is if one hopes to be respected in ones field.

You got the scene, man. Hope it’s not too late, though.

194. Aaron Wells
Posted Jul 31, 2008 at 8:18 PM | Permalink

Right you are! Thanks a bunch Eggplant Fan!

195. BarryW
Posted Jul 31, 2008 at 8:41 PM | Permalink

Steve, I hate to ask but I used your script to download the sea ice extent data, and I’d like to know how you generated the graphs. I can’t figure out how to breakup the data into years for plotting without using brute force and I’d really like to know if there is a better way of doing it. Could you point me in the right direction if this is old stuff or show the script?

Steve: If you want to pull data for a single year, I use logical vectors.

temp=(daily\$year== 2006)
plot (daily\$dd[temp],daily\$diff[temp],type=”l”) or something like that. You can define different colors as col=i; and cycle through years as 2001+i.

I should have uploaded the script when I produced the graphs as I’ve been trying to do lately. I’ll try to spend a few minutes tomorrow and upload something.

196. DeWitt Payne
Posted Jul 31, 2008 at 9:38 PM | Permalink

7/31/2008 extent projection update

The smoothed rate extent change is now -0.077286 Mm2/day compared to the maximum on 7/24 of -0.087110. I don’t expect it to keep decreasing as rapidly for the next two weeks as it is now. If it did, then the projected minimum extent would start to go up.

projected data
UL projected LL (Mm2, 95% confidence)
6.24 5.44 4.64

About a week ago there were two days in a row of over 100,000 km2 extent lost and a following day of over 90,000 km2. If CT is about a week behind, then it’s not surprising that the area data posted there was as large as it was. I should try to keep an eye on the CT area data and see if it tracks the extent rate data with a lag.

197. DeWitt Payne
Posted Jul 31, 2008 at 9:49 PM | Permalink

Phil,

If you have been keeping a record of the digital CT area data the last month or even week, I would appreciate it greatly if you would post it. It doesn’t have to be a continuous record, but each point does have to be dated. Thanks.

198. Posted Jul 31, 2008 at 10:10 PM | Permalink

Re #174

I had this conversation with Phil a few weeks ago, and he quoted this. However, he still does not realize, or does not admit, that this data is about 7 days out of date, as evidenced by comparison with the Cryosphere Today main graphs.

And as I told you then you’re wrong it is the current data, for example take today’s data, 5.238 million sq km, if it really were 7 days out of date that means it should be about 4.6, last year CT is on record as saying that the area was ~4.0 on Aug 9th, that would imply that this year is ahead of last year! Examination of the images show that that is not the case.

Re #184 both area and extent are used at different sites, one reason for using extent is that it can be more easily compared with pre-satellite data.

Re #188 Jared, I’ve been focussed on area rather than extent for years for reasons I’ve mentioned here and elsewhere, the comparison between the two measures is interesting though (plus I have a bet with lucia & Atmoz denominated in extent ;) ).

199. Steve McIntyre
Posted Jul 31, 2008 at 10:22 PM | Permalink

Day 213
Middle of the pack. 2007 has a big week coming up and my guess is that 2008 will be over 1 million sq km behind after 7-8 more days. 2006 looks in range, but not, I think, 2005.

month day year ice diff
8 1 2002 7.452 -0.08137
8 1 2003 7.617 -0.11484
7 31 2004 7.923 -0.09094
8 1 2005 6.953 -0.09297
8 1 2006 7.094 -0.04938
8 1 2007 6.324 -0.05125
7 31 2008 7.198 -0.07266

200. DeWitt Payne
Posted Jul 31, 2008 at 10:35 PM | Permalink

Phil,

You’re assuming that the area will continue to decrease at 100,000 km2/day for the next 9 days. It won’t. The inflection point in extent was a week ago. You’ve also proved that the recent 365 days data graph is indeed behind by at least three days and possibly as much as a week. The graph reaches 4 Mm2 area at a point past the August 2007 vertical line consistent with the line representing the date of August 1. The current data is still way too short of the August, 2008 mark to be consistent with it being for July 31.

201. DeWitt Payne
Posted Jul 31, 2008 at 11:05 PM | Permalink

Steve,

There’s still a lot of potential variability in 2008. It doesn’t look like it now, but things could still change in the next 50 days. At this same date, 2004 was projected as 6.18 Mm2 minimum, actual was 5.78. 2006 was projected as 5.36, actual 5.78 and 2007 was projected as 4.59, actual 4.26. It’s still too early to call anything but 2007. The projection is that 2008 will fall between 2002 at 5.65 and 2005 at 5.31, but I wouldn’t put very much money on it yet. The difference between 2002 and 2005 is about one standard deviation at the moment. So you’re looking at less than even odds that the result will fall between the two, if I did my sums correctly.

202. Posted Jul 31, 2008 at 11:31 PM | Permalink

Re #200

You’re assuming that the area will continue to decrease at 100,000 km2/day for the next 9 days. It won’t. The inflection point in extent was a week ago. You’ve also proved that the recent 365 days data graph is indeed behind by at least three days and possibly as much as a week. The graph reaches 4 Mm2 area at a point past the August 2007 vertical line consistent with the line representing the date of August 1. The current data is still way too short of the August, 2008 mark to be consistent with it being for July 31.

Dewitt, actually I built in a decline into my projection. If I’ve proved anything it’s that there’s a shift between the graph and the axis, why I know not, however there’s no doubt that the most recent datapoint is today’s data. As I said above there’s no way 5.238 is ‘old’ data.

203. DeWitt Payne
Posted Aug 1, 2008 at 12:56 AM | Permalink

Phil,

If I’ve proved anything it’s that there’s a shift between the graph and the axis, why I know not

It does seem extremely odd. You can see why it would cause me and others to think the data was not up-to-date.

Assuming that the ratio between area and extent doesn’t change drastically between now and the minimums (without data, a somewhat large assumption) for each and assuming that 5.238 is indeed data for 7/31, using the projected extent minimum of 5.44 I get an area minimum of 3.99. Using the ratio of the minimums for 2007, I get a projected minimum area of 3.83 Mm2. That’s fairly strong support for 5.238 being for 7/31.

204. Bruno
Posted Aug 1, 2008 at 1:14 AM | Permalink

Assuming the race with 2007 is over, here’s a call to raise the stakes in the race with 2005:
“The ice cover in the Arctic Ocean at the end of summer 2008 will lie, with almost 100 per cent probability, below that of the year 2005 – the year with the second lowest sea ice extent ever measured. Chances of an equally low value as in the extreme conditions of the year 2007 lie around eight per cent. Climate scientists from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association come to this conclusion in a recent model calculation.”
Source: http://www.physorg.com/news134823790.html (date: July 9th)

205. WhiteBeard
Posted Aug 1, 2008 at 1:21 AM | Permalink

#156 Gunnar,

Some good points on the physical processes involved which seems not to be appreciated by all here.

However,
“4) Humidity makes a big difference. In Utah, a lot of snow evaporates in the spring, it does not “melt”. I believe that the arctic north is a tundra, ie desert as well.”

The arctic is a desert only in the sense of annual precipitation. The context were I usually see that statement made is some a voice over of a winter scene. Where tundra exists, the cold produces “desert like” humidity values. Precipitation is highest when temperatures are also greatest, and underling permafrost prevents percolation into soils. Much of the surface is standing water after seasonal melt. Some sub-polar areas are also treeless (a defining feature of tundra) because of high absolute and average winds. All these are land forms though, not sea ice.

“5) Ice in water is often more affected by what’s happening with the water, than with the air.”

Which is quite true, but seems to ignore the effect of heat transfer from more equatorial regions through both oceanic and atmospheric circulation, or the transfer from warmer air to colder water, and ultimately floating ice. Especially in light of:

“Conclusion: melting ice is not a good indication of the average global air temperature, and therefore of AGW.”

#184 UK John,

From some comments in nosing around the U Bremen site, the extent metric is likely to be more useful than area to people doing surface navigation planning in those areas, ie research, fishing, tourism among other tasks. The 15 % coverage threshold has some utility I’d suspect. Just my inference.

206. DeWitt Payne
Posted Aug 1, 2008 at 1:37 AM | Permalink

I’m violating my rule about feeding or poking with a sharp stick things that are said to live under bridges just this once.

“Conclusion: melting ice is not a good indication of the average global air temperature, and therefore of AGW.”

Wrong. The average global air temperature isn’t all that good a measure of AGW. OTOH, the global heat content is a good measure. And melting polar ice is a very good indicator of global heat content. If the heat content of the planet goes up because of atmospheric radiative forcing, some (most?) of that heat will be transferred to the polar regions and the first thing that will happen is that the ice will melt.

207. Posted Aug 1, 2008 at 4:02 AM | Permalink

206 9Dewitt Payne):

Actually, it is you who is incorrect. Air/water temp is only one causation of polar ice melt. A much stronger reason for melt coverage is anomolous wind patterns. So, when someone says that melting ice and AGW are not strongly correlated, they are correct. Rather than call people names like bridge trolls, you would do well to read their statements more carefully, as I have no doubt you would agree with the original statement if you had the chance for retrospect.

208. Steve B
Posted Aug 1, 2008 at 7:07 AM | Permalink

snip – speculations on motive are discouraged.

209. bender
Posted Aug 1, 2008 at 7:59 AM | Permalink

#208 Speculations on motive are not encouraged and this may be the worst violation I’ve ever seen.

210. John Lang
Posted Aug 1, 2008 at 8:15 AM | Permalink

The polar 24 hour sunshine was interupted yesterday with the solar eclipse.

The Modis satellites happened to catch it in these pics. Interesting and a little bigger darkened area than one would expect, but it probably won’t effect ice extent today lol.

211. John Lang
Posted Aug 1, 2008 at 8:26 AM | Permalink

Sorry, the eclipse was today just a few hours ago, not yesterday.

212. Posted Aug 1, 2008 at 8:31 AM | Permalink

Re #203

Assuming that the ratio between area and extent doesn’t change drastically between now and the minimums (without data, a somewhat large assumption) for each and assuming that 5.238 is indeed data for 7/31, using the projected extent minimum of 5.44 I get an area minimum of 3.99. Using the ratio of the minimums for 2007, I get a projected minimum area of 3.83 Mm2. That’s fairly strong support for 5.238 being for 7/31.

Agreed, logically the assumption of a lag (which one might infer from the graph) doesn’t jibe with the images which is why I’ve always felt that it’s a flaw in the representation of the graphics and just read it as the current data.
Looking at the regional data from CT I estimate that for everywhere but the central Arctic basin the remaining melt lies between 1.0 and 1.5 sq km which would give an minimum area of 4.2-3.7. Last year the Arctic basin melted a further ~0.7 so if that happened this year we’d end up with 3.5-3.0 (equals record), if we assume a concentration of ~70% that would give an extent between 5 and 4.3.

Re #208

I wonder what Phil’s (who posts here) motives are?

You need wonder no more, I’m just interested in the science.

213. bender
Posted Aug 1, 2008 at 9:11 AM | Permalink

Re #212
I was going to point out that violation as well, Phil.

It doesn’t matter what Phil’s motives are. Look at his actions. He checks facts, points out inaccuracies and inconsistencies, demands corrections and compliance. Annoying, but functional. Sounds like auditing to me.

Steve: Quite so. He doesn’t agree; he is very welcome company here.

214. ared
Posted Aug 1, 2008 at 9:24 AM | Permalink

meanwhile, the extend reduction for day 213 has been revised to 66.000 sq. km, reaffirming 2008’s position between 2006, 2007 (~50.000 km) and 2004, 2005 (~90.000 km).

month, day, extend, loss
8, 1, 2003, 7617031, -114844
7, 31, 2004, 7922500, -90938
8, 1, 2005, 6952969, -92969
8, 1, 2006, 7093906, -49375
8, 1, 2007, 6324063, -51250
7, 31, 2008, 7203594, -66719

too bad the series is too noisy to spot the eclipse, but if the extend for today is below yesterday’s and tomorrow’s, I’ll interpret it as a result of the darkend sun anyway ;)

215. STAFFAN LINDSTROEM
Posted Aug 1, 2008 at 9:50 AM | Permalink

#213 bender, perhaps you should read a little further
back…inconsistencies…hmmm…Majority is always
wrong…?? One or two days in Kugluktuk with 20C temps
are perhaps not that important for the Arctic ice
overall melting picture…OK I am way off topic sometimes
but that’s an artform…[No Staff, tell them what it is:
smaller mental disorder…LOL] That’s why I in the mid
of Phil.’s and the rest of us somewhat animated and
confused discussion put in a link to polar bears inspecting
US submarines… Luckily they didn’t show AIT on the
sail/tower, if so the poor white bears would have died
from laughter…BTW Anybody’s seen Russian icebreaker
“Yamal” on the North Pole?? She was scheduled to be at
the NP today just in time for the eclipse…
SO BAN ALL ICEBREAKERS IN THE ARCTIC IN SUMMERTIME!!
After ten years we would know if they had an impact…??!!

PS I have no betting in ice as of today for this season,
only in Atlantic tropical systems, no money needed DS…I
hope…

216. DeWitt Payne
Posted Aug 1, 2008 at 10:00 AM | Permalink

So when does CT update? It’s nearly noon and they’re still on 7/31. JAXA updates at 11 PM Eastern Daylight. By 11:05 PM you can always count on seeing the latest data.

217. Tom C
Posted Aug 1, 2008 at 10:02 AM | Permalink

I bet the extent of summer arctic sea ice will be unprecendented…since 2005.

218. Posted Aug 1, 2008 at 10:02 AM | Permalink

#208

I don’t always agree with Phil but his observations are always well researched and well put. He is a very good counterpoint to some of the more excitable posters here, who are made to stop and think a little.
Keep on posting Phil!

Tony Brown

219. STAFFAN LINDSTROEM
Posted Aug 1, 2008 at 10:03 AM | Permalink

#214 How cold was it during eclipse, let us all hope
public…In the rest of the world the temp drops
some 10C in a couple of minutes, right!?

220. Sam Urbinto
Posted Aug 1, 2008 at 10:05 AM | Permalink

Actually you’re all wrong. And all correct. :)

In order to know what AGW is doing, you would have to already have been accurately measuring the planet’s total energy level over X years. Then you’d have to remove all non-human influence. Both of which may be a tad difficult to accomplish.

The closest we have to the first is probably satellite readings. The second isn’t really possible (I suppose it could be modeled, but what’s the point in wasting time with that?)

Ice melts or not for a number of reasons at a location; wind patterns and speeds, precipitation levels and types, humidity levels, cloud cover, strength and duration of sunlight, water motion and temperature, soot or other contamination, thickness and weight… The tricky part is separating them, no?

So. Just one aspect. In order to get precipitation, you have to get to the dew point by cooling, or saturate it by adding more water.

Cooling:
A) Conductive: Warm air moving over a cool surface
B) Convective: The air lifting
C) Evaporative: Liquid phase change to vapor
Saturating:
A) Precip from higher above
B) Dry air moving over open water
C) Sunlight evaporating liquid water

Not too different, eh? So what percent is what? And do we get hail, snow, rain or sleet?

AGW signature indeed.

221. UK John
Posted Aug 1, 2008 at 10:16 AM | Permalink

I know Phil is needed it would be pointless if we all just agreed.

The only thing is that some people, like me, saw all these various metrics, :- Area, Extent, Concentration etc etc. wondered what they all meant, how they were defined, measured, recorded, analysed, etc. etc. found out from the people producing the results why they did things the way they do.

I did all this without anyone like Phil, or Steve, “helping” me and reached a conclusion.

All these metrics tell you something, but I did learn they are only a small part of the story.

Another part of the story is that the sea ice comes and goes, and that the ice caps come and go, nowhere is there an “unprecedented” situation, it has all happened before, and all of this had nothing to do with us, uptil now, MAYBE!.

222. DeWitt Payne
Posted Aug 1, 2008 at 10:27 AM | Permalink

CT finally updated. 8/1/2008 5.218 Mm2. That’s a change of 0.01 Mm2, pretty small compared to the 0.10 change from 7/30 to 7/31.

223. DeWitt Payne
Posted Aug 1, 2008 at 10:33 AM | Permalink

Sorry, 0.02 not 0.01. Still pretty small and the average for the two days is 0.06 or pretty close to what the extent is doing. I’ll try to do this every day, but because the data seems to evaporate, it would be helpful if others could look as well and post the daily result if I miss it for some reason. This is the site: http://arctic.atmos.uiuc.edu/cryosphere/iphone/iphone.currentarea.series.html

224. BarryW
Posted Aug 1, 2008 at 10:46 AM | Permalink

Thought this might be another way of looking at the run just before the turn by graphing the differences in extent pairwise against 2008.

If I did this right 2008 is losing ground to 2003, gaining slightly on 2005, and maintaining it’s lead on 2006, but just barely. I only mapped the four pairs so it wouldn’t look too cluttered.

225. BarryW
Posted Aug 1, 2008 at 10:54 AM | Permalink

Arg, that didn’t work

226. STAFFAN LINDSTROEM
Posted Aug 1, 2008 at 10:57 AM | Permalink

#223 Tnx for the link, DWP..[I’m as reluctant as you
are to use RP to use Apple software and applications,
I have QTP but nowadays I use it once or twice a year,
anyhow RP11 IS nifty for DL of YouTube-videos, but be sure
they are “free”…]
For all interested in Arctic ice: A googling of
“transpolar drift” is not too bad, I think [SMHI IS
ONE SOURCE…I owe them that…]

227. John Lang
Posted Aug 1, 2008 at 11:00 AM | Permalink

The sea ice is back in Barrow Alaska. An intense low in the Beaufort Sea has dropped temperatures, caused new ice to form, snow to fall in Barrow and pushed ice up on the coast.

228. STAFFAN LINDSTROEM
Posted Aug 1, 2008 at 11:39 AM | Permalink

#227 John Lang … that Barrow wx certainly reduces the
famous Barrow UHI…[google that, folks] Not much above
zero in the coming 180 hours [Wetterzentrale] As Steve
Sadlov pointed out, Anchorage is struggling NOT to break
its minimum record of days not exceding 65F, NOT Steve

229. Posted Aug 1, 2008 at 12:15 PM | Permalink

Re #228

Staffan, this is why I earlier referred to the warm weather at Kugluktuk, in response to someone mentioning the cold weather in Anchorage (I think) as if it were some event of great import. I noticed on the CT map today that the offshore ice had blown towards the shore, I also noticed that Alert is currently experiencing quite balmy weather (sunny and 15ºC). ;)

230. bender
Posted Aug 1, 2008 at 12:35 PM | Permalink

#229 Quite agree. A global surface temperature anomaly map says a thousand words.

231. bender
Posted Aug 1, 2008 at 12:41 PM | Permalink

Before filing a weather report at CA, why not build a global anomaly map in order to come clean on your coefficient of cherry-picking:

http://data.giss.nasa.gov/gistemp/maps/

232. John Lang
Posted Aug 1, 2008 at 12:47 PM | Permalink

I can give you a weather synopsis for the entire Arctic Ocean if you like – approximately -2.0C – the temperature which produces a moderate amount of sea ice melting each day.

233. See - owe to Rich
Posted Aug 1, 2008 at 1:02 PM | Permalink

Hey guys I think we should stop worrying about how fast the Arctic is melting, which we weren’t really, and start worrying about why the Antarctic is starting to melt 2 months early. OK, it’s probably just a blip, but it’s the first time for ages that I’ve seen the anomaly be lower than 365 days ago.

Rich.

234. bender
Posted Aug 1, 2008 at 1:05 PM | Permalink

-2.0C – the temperature which produces a moderate amount of sea ice melting each day

If it’s glancing blows you would like to exchange …
Surface air temperature, over short time-scales, is not the driver that ocean heat content, over longer time-scales, is.

235. jeez
Posted Aug 1, 2008 at 1:16 PM | Permalink

The baby is ice is lost, confused, but will find its way home.

236. bender
Posted Aug 1, 2008 at 1:42 PM | Permalink

#235 Cousteau, is that you?

237. John Lang
Posted Aug 1, 2008 at 1:45 PM | Permalink

Well, it looks like Roald Amundsen could probably get through the NorthWest Passage today with the same ship and taking the same route he did south of King William Island. After spending two winters frozen in at King William Island (some of which was on purpose), his ship left the Island on August 14th 1906 after the ice became navigable. The rest of the routes are still closed but you can probably get to the rock shoal-filled strait south of the Island and the rest of the way is open.

http://en.wikipedia.org/wiki/Image:King_William_Island.svg

238. Posted Aug 1, 2008 at 2:07 PM | Permalink

post 233

according to a thread on some blog called climate audit the antarctic is cooling

http://www.climateaudit.org/phpBB3/viewtopic.php

Tony Brown

239. jae
Posted Aug 1, 2008 at 2:30 PM | Permalink

231, bender:

Before filing a weather report at CA, why not build a global anomaly map in order to come clean on your coefficient of cherry-picking:

http://data.giss.nasa.gov/gistemp/maps/

Curiously, if the Time Interval selected is 2,000 or later to 2007, no anomalies are shown for the land surfaces. ??

240. bender
Posted Aug 1, 2008 at 2:42 PM | Permalink

#239
Works for me.

241. Aaron Wells
Posted Aug 1, 2008 at 3:58 PM | Permalink

NSIDC has done another update:

From the August update:

Overview of conditions
Arctic sea ice extent on July 31 stood at 7.71 million square kilometers (3.98 million square miles). While extent was below the 1979 to 2000 average of 8.88 million square kilometers (3.43 million square miles), it was 89,000 square kilometers (35,000 square miles) above the value for July 31, 2007. As is normal for this time of year, melt is occurring throughout the Arctic, even at the North Pole.

They’re only off by about a factor of 10! It should be closer to 890,000 square kilometers.

242. Aaron Wells
Posted Aug 1, 2008 at 4:01 PM | Permalink

For some reason the NSIDC link didn’ appear.

Here it is:

NSIDC

243. STAFFAN LINDSTROEM
Posted Aug 1, 2008 at 7:29 PM | Permalink

#241 Aaron Wells, is that little spot S of the NP with 40-50 percent
ice concentration not just a little armada of nuclear icebreakers including
the fierceful “Yamal” with her 48mm thick double-hull and painted
shark jaws…?? These guys AND dolls (NSIDC) sit in Boulder CO, “Mork and
Mindycity”…so I’m not surprised their number was wrong by a factor of 10…
LOW JOKE, Staff…Meanwhile here in Sweden, last night Pajala 67.21N, 23.4E,
RECORDED MINUS 0.3C …Unprecedented since 1977 on that date! Since 2001 no frosts at
all in August except last night of 2003…and chill: 3 possibly 4 nights
late in August last year…[one day missing in TuTiempo stats…]

it an order!!…Choose .mov file 7.5 MB AND VLC player, QUICKtime sucks! [Sorry
again Apple…]
MORE2 UIUC Compare daily sea ice compare 1993 Sept 1 to 2007 Sept 1 …and
let me hear your judgements…! It’s definitely an order [lol]

244. STAFFAN LINDSTROEM
Posted Aug 1, 2008 at 7:45 PM | Permalink

#243 Appendum NSIDC wrong by a factor of 10, somewhere the other week I
read about 2 NSIDC scientists there who firmly believed that if warming
continues as business as usual, the Greenland icecap has less than
500 years of existence, therefore every little Ward Island ice is potentially
like the Titanic iceberg but the other way round…So I give Greenland
ice 5000 years…Prolonged cyberdisc life, someone??

245. TAC
Posted Aug 1, 2008 at 9:13 PM | Permalink

Day 214

A big day for 2008, but it continues to fall behind 2007

8 2 2002 NA NA
8 2 2003 7.531250 -0.085781
8 1 2004 7.859688 -0.062812
8 2 2005 6.910156 -0.042813
8 2 2006 7.038750 -0.055156
8 2 2007 6.217500 -0.106563
8 1 2008 7.097188 -0.106406

246. Hemst 101
Posted Aug 1, 2008 at 10:38 PM | Permalink

Re NSIDC

“Arctic sea ice extent on July 31 stood at 7.71 million square kilometers (3.98 million square miles). While extent was below the 1979 to 2000 average of 8.88 million square kilometers (3.43 million square miles), it was 89,000 square kilometers (35,000 square miles) above the value for July 31, 2007. As is normal for this time of year, melt is occurring throughout the Arctic, even at the North Pole.”

Who are these Bozos? 7.71 Sq Kms = 3.98 Sq Miles
8.88 Sq Kms = 3.43 Sq Miles

And they are out an order of magnitude re the difference between July 2008 and July 2007. Is this indicative of the mathematical quality of NASA? Are these guy in the Ice division demotions from the crashed Mars Polar explorer? Maybe a editing problem but really!!

247. STAFFAN LINDSTROEM
Posted Aug 2, 2008 at 12:04 AM | Permalink

#244 Correcting myself,…”Ward Island” …SHOULD BE:..
“Ward Hunt Island”…

#246 So AGW perhaps is only a METRIC-OLD ENGLISH MILES-
MEASURING CONVERSION problem?? Very, very tiny part in
a very few, hopefully, cases…I have found something,
but release party is later…Meanwhile I prefer Miles
Davis…BTW I think Robin Williams is pro-AGW, but
in a new series: “Mork and Mindy and the Bozos” he is
coming to realize everything is not black OR white

248. jeez
Posted Aug 2, 2008 at 12:21 AM | Permalink

bender, you may not believe this, but I spent six months scriptwriting and video editing for The Cousteau Society way back in 91.

249. BarryW
Posted Aug 2, 2008 at 12:47 AM | Permalink

2007 is not really falling behind in total extent it’s actually closed a little:

Here are the extent differences for the last four days between 2007 less 2008

-0.911406 -0.896094 -0.895000 -0.879531

When you look at the differences 2008 is gaining on 2005 but 2006 has almost caught up with it.

250. STAFFAN LINDSTROEM
Posted Aug 2, 2008 at 1:05 AM | Permalink

#216 DWP, around 21:00 GMT, give or take an hour or two,
have’nt checked every 15 minutes, like you pros do…LOL

251. jeez
Posted Aug 2, 2008 at 1:13 AM | Permalink

RE 246:

Who are these Bozos? 7.71 Sq Kms = 3.98 Sq Miles

It’s a typo 7.71 Sq Kms = 2.98

But the order of magnitude thingy? well, that’s another story…

Baby Ice gets no respect.

252. jeez
Posted Aug 2, 2008 at 1:13 AM | Permalink

7.71 Sq Kms = 2.98 Sq Miles that is.

253. STAFFAN LINDSTROEM
Posted Aug 2, 2008 at 1:56 AM | Permalink

#245 TAC … I have a hard time looking at the JAXA site
in finding a 106000 sq kms loss from last of July to August 1…
CT has no ice left in Hudson Bay, whereas JAXA has, could it
be that?? N Beaufort Sea is dispersing probably due to that low
N of Alaska, but dispersion is one thing and disappearance another??
According to JAXA Arctic SST inreased from -1.4C in 2004 to -0.8C in
2007…But they were as high in 2000…Same period salt content
decreased from 2.7 % to 2.4 % approximately…[When salt content hits
bottom close all entrances…and exits…LOL]

254. bender
Posted Aug 2, 2008 at 2:11 AM | Permalink

#248 That’s too funny. When you encourage baby ice, it’s His voice I hear.

255. jeez
Posted Aug 2, 2008 at 2:22 AM | Permalink

Here’s all I can give you in five minutes:

Seemingly plunged into a downward spiral of accelerating destruction, the baby ice cautiously and at the same time playfully relies on instinct, not courage to survive to another season.

It is this instinct, carved and molded by generations of ice that came before, that protect and sustain the baby ice throughout the treacherous long summer season.

After beating back the solar onslaught, the now exhausted baby ice crawls slowly towards the safety and comfort of the long winter nights, finally to rest, to heal, to strengthen, and thus to perpetuate nature’s glorious ice dance of the seasons.

256. jeez
Posted Aug 2, 2008 at 2:29 AM | Permalink

It is important to note that before we submitted a script to Jean-Michel or Jacques for reading session in the sound booth, the writing team had to vet the script together by a process we called “Fudding”. You had to read the script out loud as Elmer Fudd would and if it sounded too ridiculous it needed to go back for a rewrite.

Jean-Michel and Jacques struggled with “th” sounds, so every once in a while we’d slip in a joke script with items like “three-toed sloth” to watch them choke and stumble in the booth. Good times.

257. MrPete
Posted Aug 2, 2008 at 3:35 AM | Permalink

Jeez that is AWESOME!

Folks, gotta read Jeez #255 slowly and with feeling, preferably out loud, to get the full impact. Wow, this is better than polar bears.

258. crosspatch
Posted Aug 2, 2008 at 3:47 AM | Permalink

And today, in Barrow, it snows.

259. TAC
Posted Aug 2, 2008 at 4:48 AM | Permalink

Jeez (#255): “The Society for the Prevention of Cruelty to Baby Ice” has found its voice:

Seemingly plunged into a downward spiral of accelerating destruction, the baby ice cautiously and at the same time playfully relies on instinct, not courage to survive to another season.

It is this instinct, carved and molded by generations of ice that came before, that protect and sustain the baby ice throughout the treacherous long summer season.

After beating back the solar onslaught, the now exhausted baby ice crawls slowly towards the safety and comfort of the long winter nights, finally to rest, to heal, to strengthen, and thus to perpetuate nature’s glorious ice dance of the seasons.

AWESOME!

Have you considered voicing over some B roll footage and putting this on youtube?

Barry (#249):

007 is not really falling behind in total extent

You’re right: 2008 has closed on 2007 over the past few days.

Steffan (#253):

I have a hard time looking at the JAXA site in finding a 106000 sq kms loss

I don’t know how to answer that one.

260. STAFFAN LINDSTROEM
Posted Aug 2, 2008 at 5:13 AM | Permalink

Baby Ice…SORRY Couldn’t resist…
TAC You saw the JAXA images??, not much change??

261. Aaron Wells
Posted Aug 2, 2008 at 8:16 AM | Permalink

You’re right: 2008 has closed on 2007 over the past few days.

The difference between 2008 and 2007 recently have been quite trivial.

Below I have a link to a graph which tracks the differences in ice extent between 2008 and other years.

Sea Ice Extent Difference from 2008

262. steven mosher
Posted Aug 2, 2008 at 9:07 AM | Permalink

Staffan. I thought you were Gold Bond.

http://www.goldbond.com/gold-bond-products.html

263. crosspatch
Posted Aug 2, 2008 at 10:28 AM | Permalink

It has been much warmer and sunnier in the far Northern arctic region. Looks like +3.5C and brilliant sunshine at the pole today.

264. BarryW
Posted Aug 2, 2008 at 11:20 AM | Permalink

Re #261

Yes, it’s trivial but still a small bit closer. The real change is in the relationship to 2006. If the rate of change keeps up 2008 will be below it fairly soon. The other years’ differences seem to be relatively stable over the last few days.

265. STAFFAN LINDSTROEM
Posted Aug 2, 2008 at 3:56 PM | Permalink

#262 Mosh…1. Please watch the 453 YouTube videos “Gold Bond” and give me
2. Please compare CT and JAXA arctic ice concentration maps, why
are they so DIFFERENT??
3. Me Gold Bond??????? Ernest GOLD wrote music for the movie/film
“Exodus” and last summer saw an “ice exodus” via the waters east
of Greenland and some other places too…
4. For all … The coming week will be cloudier and somewhat milder
than the last days. Snow on ice is important, albedo-wise…There
is at the moment still a small risk/chance that 2008 catches up 2007!
5.The years 2002-2004 the arctic ice didn’t melt from below so much
because of lower SST…

266. Posted Aug 2, 2008 at 5:56 PM | Permalink

Re #265

2. Please compare CT and JAXA arctic ice concentration maps, why
are they so DIFFERENT??

You’re kidding?

267. STAFFAN LINDSTROEM
Posted Aug 2, 2008 at 8:13 PM | Permalink

#266-269 jeez, mosh, Phil….No, not drunk … FYI
There are no bars like in USA in Sweden where you can just
slip in on your way from/to work and and have a glass or 10….
We have restaurants with bar compartments, besides drunk people
tend to pour liquids in your ASUS EEE to test if it can get in-
toxicated…Not even a beer at home, reading CA postings are
quite enough, tnx…LOL…
Phil. Not kidding, erring…!! Not CT, UIUC CDSI…But AGAIN
looking at JAXA where is THE LOSS OF 106000 SQ KMS FROM 07/31/08
TO 08/01/08???

268. TAC
Posted Aug 2, 2008 at 9:04 PM | Permalink

Preliminary Unofficial Day 215 Race Report
2008 had another day with melt exceeding 100000, though still losing some ground to 2007
8 3 2002 NA NA
8 3 2003 7.458594 -0.072656
8 2 2004 7.755313 -0.104375
8 3 2005 6.866719 -0.043437
8 3 2006 6.967188 -0.071562
8 3 2007 6.109844 -0.107656
8 2 2008 6.997344 -0.103594

269. BarryW
Posted Aug 2, 2008 at 9:25 PM | Permalink

Re 268

My guess is that 2008 will pass 2006 and 2005 by day 217

270. Aaron Wells
Posted Aug 2, 2008 at 9:44 PM | Permalink

My guess is that 2008 will pass 2006 and 2005 by day 217

2006, yes there’s a good chance.

2005, no way. Currently the differential is 130625 km^2. 2005 is going to lose 188,283 km^2 in the next 2 days. That means 2008 would have to lose (130625 + 188283) = 318908 km^2 in the next 2 days for 2005 to catch up. That’s not going to happen, or even come close. At best, the margin might drop from 130,625 to around 100,000 km^2.

271. BarryW
Posted Aug 2, 2008 at 9:51 PM | Permalink

Re 270

You’re right, once I hit the submit button I wanted to take that back. I still think it will catch 2005 but nowhere near that quick.

272. DeWitt Payne
Posted Aug 2, 2008 at 9:59 PM | Permalink

The odds of 2008 catching 2005 are indeed looking better. The projected minimum for 2008 is now 5.39 Mm2 (UL 6.13, LL 4.66 ) compared to the minimum extent of 5.31 Mm2 for 2005. The loss rate for 2005 drops to below average very soon and stays there for quite a while. OTOH, 2005 has a significantly above average loss rate not long before the minimum date, but by that point, the loss rate is not large.

Ice area (CT) for 8/1 is 5.165 for a difference of -0.053 from 7/31. The average from which the anomaly is calculated shows an average loss/day of 0.075 for the last two days. So the anomaly has decreased to -1.223 from -1.300 on 7/30. Interestingly ice area and ice extent anomalies seem to be going in opposite directions.

273. Aaron Wells
Posted Aug 2, 2008 at 10:13 PM | Permalink

NSIDC has really gone off the deep end with their latest ice extent chart! Check out the drop in ice extent in the past 2 days! Its like it dropped off a table. They have the ice extent dropping by about 500,000 km^2 in the past 2 or 3 days! According to my tracking of IARC/JAXA ice extent data, it has taken approximately 8 days to lose that much extent. 8 days would be 1/4th of the distance between the July to August tick marks. That graph is baloney. These guys are really sloppy!

NSIDC Arctic Sea Ice Extent Graph

STeve: Why don’t you contact them and ask them for the location of the digital information underpinning this graph?

274. DeWitt Payne
Posted Aug 2, 2008 at 10:29 PM | Permalink

Aaron W.

I think it has something to do with their data smoothing. My extent chart looks more or less like theirs, but it’s a lot bumpier. There was a period of reduced slope followed by the last two days of increasing slope. It looks like their smoothing moved the inflection point back a few days, but the end point of the 2008 graph looks about right.

275. Leon Brozyna
Posted Aug 2, 2008 at 11:04 PM | Permalink

Aaron W #273

You’re right. Been checking each day’s update regularly and around noon Saturday the line tracing the melt rate seemed to have been slowing down for the past few days with the updated figures through 31 July. A few hours later the line suddenly changed direction with a new updated chart for 1 August. It’s like several days of decreasing melt rate was suddenly changed to increasing melt rate. Rather than approaching the average melt rate, it’s now rushing to meet last year’s melt rate. Probably will be explained as a result of all that thin 1-year ice.

I’m still waiting to see how the refreeze proceeds this fall/winter season. I’ll also be watching to see if there is any further ‘tweaking’ of the data.

276. Posted Aug 2, 2008 at 11:27 PM | Permalink

Re #275

Some interesting ice thickness from a few of the buoys that measure it, this one is particularly interesting because it show two seasons. It looks like it will go significantly below 1m this month:

277. DR
Posted Aug 2, 2008 at 11:28 PM | Permalink

What effect does cloud cover change have on Arctic ice melt?

http://www.arm.gov/science/research/pdf/R00143.pdf

278. Posted Aug 2, 2008 at 11:32 PM | Permalink

Don’t know what happened there, try again:
Ice thickness

279. DeWitt Payne
Posted Aug 2, 2008 at 11:57 PM | Permalink

Phil,

Interesting, but still anecdotal. That is, it’s just one point and that point isn’t even in the same place as the year before. Ice thickness may well be lower now than it was 30 years ago. The MSU readings for the Arctic (60 to 82.5 latitude) show a substantial positive anomaly starting in 1995. However, that warming may have peaked. This plot is only through April, 2008, but the apparent trend hasn’t changed in the last two months. That’s an exponentially weighted moving average plot with an alpha of 0.08.

280. Posted Aug 3, 2008 at 1:42 AM | Permalink

I am going on holiday now for two weeks. Jeez is nominated to look after Baby Ice and nurse it whilst I am away through the next few difficult weeks. Look out for Phil, I think he means Baby Ice harm.

I am fearful of warm weather, after all here in the UK the August 2nd temperatures were unprecedented-the highest since 2007.

TonyB

281. jeez
Posted Aug 3, 2008 at 1:52 AM | Permalink

I accept the responsibility. Phil–back off!

282. Vincent Guerrini Jr
Posted Aug 3, 2008 at 3:12 AM | Permalink

Looks like NH ice is reversing now. Have a look at all the main ice maps…link to “Cryosphere today” 1/08/08. If so, NH will probably be back to normal quite soon.

283. Andrey Levin
Posted Aug 3, 2008 at 3:37 AM | Permalink

Staffan Lindstroem:

Take the matter in your own hands:

http://www.homebrewers.com/

284. MrPete
Posted Aug 3, 2008 at 5:53 AM | Permalink

Phil (and others creating image links)… some of the troubles you’ve had recently:
* Can’t do an image link to an html page. Gotta use IMG with gif/jpg/png/etc, and A with html/etc
* Got to get those quotes immediately to left/right of the linked URL

Hope that helps

285. DeWitt Payne
Posted Aug 3, 2008 at 9:03 AM | Permalink

MrPete,

Is it better for the server to use a link to an image or is it OK to use the img tag (correctly)?

286. Posted Aug 3, 2008 at 9:29 AM | Permalink

Re #279

Hardly anecdotal but yes it is only one point. Although that ice has moved this year it’s been heading straight for the N pole and is above 85º but is still showing strong melting (~1m in July). This is not in the area where the ice is shown as fragmented so it implies that there’s more happening than we see with satellites.
Regarding the MSU results as you say they don’t cover the Arctic Ocean so that’s a problem but when I looked at this spring’s plots there looked to be lots of red up there!
If we’re entering cool phase of the PDO that would lead to increased SST anomalies in the N Pacific: PDO counter intuitive but the phases are named according to their effect on the N American coast not overall.

Re #284
Yes I know, I thought I’d saved the jpg address but apparently hadn’t, it was late. :(

287. DeWitt Payne
Posted Aug 3, 2008 at 10:20 AM | Permalink

I’ve developed a way to calculate a projected date for minimum extent, I think. I take the projected minimum extent, subtract it from the actual extent then compare this difference to the average remaining extent to minimum for 2002 to 2007 (extent-minimum for that year). That gives me the number of days left to minimum extent, from which the date for 2008 can be calculated. Right now the projected date of minimum extent is between 9/14 and 9/15. The range of minimum extent date for 2002 to 2007 is 9/9 to 9/24. A lower projected minimum extent means a later date and conversely. I’ve looked at 2007 and it sort of works and that should be the worst case.

288. MrPete
Posted Aug 3, 2008 at 11:08 AM | Permalink

Link (A) vs Image (IMG)… depends on the thread. The server doesn’t care, but when a thread has a hundred images to load, users’ browsers slow down. Links take up less visual space, images can be seen immediately. Gotta use common sense ;)

289. DeWitt Payne
Posted Aug 3, 2008 at 11:12 AM | Permalink

Phil,

Anecdotal in the sense that you have posted the results from only one buoy. This is exactly equivalent to a drug trial where you give the drug to just one person. Assuming the person doesn’t die instantly, you cannot draw a conclusion about the safety or effectiveness of the drug. That is referred to as anecdotal evidence. Anecdotal doesn’t necessarily mean untrue. The statement: ‘My father smoked like a chimney and lived 104 years’ is an anecdote. It may well be true, but it says nothing about the safety of smoking for anyone other than the person referred to in the anecdote. I’m sure the data from the buoy is accurate, but it’s just one point. It does no more than suggest the possibility that all the ice in the Arctic is thinning. It only absolutely falsifies the statement that all the ice in the Arctic ocean is getting thicker.

The NoPol MSU data is very noisy. You can’t look at just a few months and draw a conclusion. This is raw and smoothed data starting January, 2007.
raw EWMA smoothed
0.59 1.02
1.37 1.05
0.37 1.00
1.68 1.05
0.06 0.97
1.67 1.03
1.43 1.06
1.09 1.06
0.00 0.98
1.02 0.98
0.77 0.96
1.12 0.98
0.12 0.91
0.64 0.89
0.51 0.86
0.18 0.80
1.04 0.82
0.49 0.79

The maximum positive NoPol (land and sea) anomaly was 2.25 on April, 1995. The month before the anomaly was -0.44 and the month after it was 0.98. The smoothed anomaly for 4/95 was 0.16.

Also, from January, 1995 to December 2006 the smoothed temperature was increasing at a rate of 0.81 C/decade. If you subtract that trend from the data, the temperature change is even more striking.

290. DeWitt Payne
Posted Aug 3, 2008 at 11:28 AM | Permalink

CT sea ice area 8/3/2008 5.160 Mm2 difference -0.005 anomaly -1.162

They appear to have updated the iPhone page but not the main page yet.

#233,

The Antarctic ice hasn’t come close to peaking yet. There are pauses and even short reversals from time to time. Peak extent isn’t expected for over 45 days plus or minus a week or 10 days.

291. BarryW
Posted Aug 3, 2008 at 9:01 PM | Permalink

NSIDC is saying the folowing

The Arctic sea ice is now at the peak of the melt season. Although ice extent is below average, it seems less likely that extent will approach last year’s record low.
The pace of summer decline is slower than last year’s record-shattering rate, and peak sunlight has passed with the summer solstice. However, at least six weeks of melt are left in the season and much of the remaining ice is thin and vulnerable to rapid loss. A race has developed between the waning sunlight and the weakened ice.

Go Baby Ice!

292. TAC
Posted Aug 3, 2008 at 9:11 PM | Permalink

Preliminary Unofficial Day 216 Race Report
2008 has a slow day.
8 4 2002 NA NA
8 4 2003 7.350313 -0.108281
8 3 2004 7.693750 -0.061563
8 4 2005 6.776719 -0.090000
8 4 2006 6.879375 -0.087813
8 4 2007 6.001250 -0.108594
8 3 2008 6.909688 -0.086406

293. jeez
Posted Aug 3, 2008 at 9:34 PM | Permalink

Weakened, but not crippled, the baby ice seeks comfort in numbers, huddling together to fend off the waning, but still dangerous attacks of the sun, rain, and wind.

For in this battle between nature’s adversaries, time is the referee, the arbiter of success, and survival the only means to victory.

Soon, the exhausted baby ice will know either the joy of returning home to flow another year, or the endless peace of failure.

294. DeWitt Payne
Posted Aug 3, 2008 at 10:25 PM | Permalink

The 2008 projected minimum is still 5.39 Mm2 on 9/15. 2006 has only one more day of extent loss as big as what 2008 is doing now so I expect 2006 will be caught and passed soon. Still I can only rule out 2007 at 95% confidence on the low end and 2003 at 90% confidence on the high end. All other years are still have a better than 10% chance of being caught, but only 2005 on the low end is close to even odds.

I wouldn’t call a loss of extent of 0.086 Mm2 a slow day, more like average or slightly above average for this time of year.

295. Vincent Guerrini Jr
Posted Aug 4, 2008 at 3:55 AM | Permalink

re world ice: After having observed anomalies in south America for at least 12 months
http://wxmaps.org/pix/temp8.html it’s interesting to note the constant cooling (12 months +)occurring in the andes (All) One would presume that the glaciers here would be increasing (If precipation was normal over same period)?

296. Aaron Wells
Posted Aug 4, 2008 at 8:22 AM | Permalink

Can Aaron Wells do another of the daily 2007 and 2008 graphs? Thanks.

Hi Andy,

Here are the graphs that I update daily:

Sea Ice Extent Daily Reductions Day 216

Sea Ice Extent Day 216

2008 Ice Extent Differences From Previous Years Day 216

Steve: I presume that you are using the JAXA data? It would be helpful if you noted the data provenance.

297. Aaron Wells
Posted Aug 4, 2008 at 8:31 AM | Permalink

Here is a modified version of the Sea Ice Extent Day 216, with a different aspect ratio. The previous one was a bit too vertical.

Sea Ice Extent Day 216

298. BarryW
Posted Aug 4, 2008 at 8:54 AM | Permalink

Re 294, 295

It’s slow relative to what it was doing previously. It’s been tracking closer to 2007 than 2006 in melt rate over the last few weeks.
It looks like the next couple of days will tell. If the 2008 melt rate slows it may be following a 2006 track and not even break 2006 (or break it by much)
Unless the rate picks up dramatically it’s pulling away from 2007.

299. Aaron Wells
Posted Aug 4, 2008 at 9:22 AM | Permalink

Steve: I presume that you are using the JAXA data? It would be helpful if you noted the data provenance.

Yes. It is the daily IARC/JAXA data that is released at 11:00pm (East-Coast US Time)nightly with preliminary data for that day, and finalized around 10:00am the next morning. I have indicated in the past that it is based upon IARC/JAXA data, but I sometimes forget that this thread has gotten quite long, and I should show list the source each time. I will try to remember to do that in future posts.

300. DeWitt Payne
Posted Aug 4, 2008 at 11:16 AM | Permalink

Cryosphere Today Recent NH Sea Ice Area:
posted at noon 8/4/2008
area difference anomaly
5.117 -0.043 -1.142 Mm2

The last 5 days have averaged a rate of -0.06 Mm2/day, somewhat below the 1979-2000 average as evidenced by the decrease in the anomaly from -1.300 to -1.142. I think it’s interesting that the area loss is below average while the extent loss over the same days was higher than average. Apparently there has been consolidation and ice from some low concentration areas has been pushed together. It’s only a few days data so I can’t be very confident that this trend will continue.

301. jeez
Posted Aug 4, 2008 at 11:26 AM | Permalink

See Post 293.

302. Jedwards
Posted Aug 4, 2008 at 4:35 PM | Permalink

Re: 297, 298

Great job Aaron! Minor quibble (very minor), I’d rename your graphics as Daily ARCTIC Sea Ice Extent, we don’t want others to get confused since the ANTARCTIC is melting away sooooo much faster (NOT!).

303. markinaustin
Posted Aug 4, 2008 at 6:19 PM | Permalink

has anyone else noticed that the Antarctica looks like it is on track to make a good run at last year’s record? if you take last year’s record ice in the Antarctic and you have 1 million less melt off in the arctic this year, we should be VERY close to average for the overall ice…..

304. DeWitt Payne
Posted Aug 4, 2008 at 6:39 PM | Permalink

The Antarctic area anomaly is currently -0.196 Mm2. To set a record, it would need to be greater than 1.0. 2008 was running ahead of the average for most of the year until the recent pause. So no, I don’t think Antarctica is on track anymore to make a run at last year’s record. Also, the global sea ice anomaly, which is sum of the Arctic and Antarctic is -1.338 Mm2. That’s well below average, although not in record low territory either. You can see a plot of the global anomaly from 1979 to the present in the lower part of the home page or an expanded version here: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg.

305. markinaustin
Posted Aug 4, 2008 at 7:02 PM | Permalink

i must be reading the graph wrong and i don’t know where you grabbed the data (not doubting you just don’t know where that is from). looking at the graph i posted, it looks to be VERY close to where it was last year at the exact same point. not quite as high, but very close. am i reading that wrongly?

306. TAC
Posted Aug 4, 2008 at 9:07 PM | Permalink

Preliminary Unofficial Day 217 Race Report
2008 has a really slow day.
8 5 2002 NA NA
8 5 2003 7.280156 -0.070157
8 4 2004 7.620938 -0.072812
8 5 2005 6.678438 -0.098281
8 5 2006 6.795000 -0.084375
8 5 2007 5.890469 -0.110781
8 4 2008 6.849531 -0.059532

307. Aaron Wells
Posted Aug 4, 2008 at 9:48 PM | Permalink

2008 has a really slow day.

You can say that again. This was a significant day for 2008. This was one of the very rare days that 2008 lost less extent than every other recent year! (Although it also occurred about 8 days ago too).

Also significant is that just when 2006 was just about to overtake 2008, 2008 fought it off by nearly doubling it’s margin over 2006 from 29688 km^2 to 54531 km^2. Now, to be honest, this turn of events between 2008 and 2006 is likely to be short-lived as 2006 is just about to enter an extended period of very low area reduction. So unless 2008 has the same dramatic slow-down in extent area reduction as 2006, it is very likely that 2006 will manage to catch up and pass 2008 in ice extent area.

308. DeWitt Payne
Posted Aug 4, 2008 at 9:52 PM | Permalink

No. It’s indeed very close to where it was last year at this time. But that has nothing to do with setting a new record. The anomaly both last year and now is close to zero. To set a record, the anomaly will have to go over 1. The extent increase last year from the same date was unusually large. There is no reason to believe that this year’s increase will be as large or larger. If there was indeed a connection between the high area in the Antarctic and the low area in the Arctic, then the expected higher Arctic extent this year predicts normal extent in the Antarctic. If the anomaly remains at the 1979 to 2000 average, then this year’s peak extent will be nearly 1,000,000 km2 lower than last year. That doesn’t mean it won’t set a new record this year, but based on the fact that the anomaly has been less than 1 over 90% of the time from 1979 to the present, it’s very unlikely.

309. DeWitt Payne
Posted Aug 4, 2008 at 10:06 PM | Permalink

Projected minimum extent went up a little to 5.42 Mm2, still between 2005 and 2002, and the predicted minimum date is still 9/15. In the next week, I project that 2008 will lose about 200,000 km2 more extent than 2006.

310. jeez
Posted Aug 4, 2008 at 10:10 PM | Permalink

Twenty-four long, grueling hours have passed and it is time to for that painful but necessary census of the unmelted—those last hardy remainders of the baby ice pod that still fights for its survival.

No sound is heard as the pod clusters together, communicating via touch who still lives and via absence those now wet souls who will be forever missed.

Seemingly sentient, the pod of baby ice stiffens, gaining resolve, bracing for the ongoing battle with the elements, and although it makes no sense, apparently leaning into the wind, as if gesturing, “bring it on!”

311. Aaron Wells
Posted Aug 4, 2008 at 10:35 PM | Permalink

… the endless peace of failure.

… absence those now wet souls who will be forever missed.

Jeez, will you write my eulogy when I die? ;-)

312. markinaustin
Posted Aug 5, 2008 at 12:15 AM | Permalink

thanks De Witt…that helps. i am not clear on what you are doing in terms of predicting, but i trust that you are reasonable. it will be interesting to watch.

still, all in all, it feels like we are WELL within average for the past 30 years and nothing is happening that we should be terribly alarmed by in my estimation.

313. AndyW
Posted Aug 5, 2008 at 5:49 AM | Permalink

Thansk Aaron again for those graphs, is there a link for them in general so I do not have to keep asking?

#313

Anomaly graphs are here.

NH

SH

Total

The total seem to show a slight dip trowards the end but I am not sure how much you can read into that nor whether it fits into your “within average” definition.

I’m going to bet on 5M Km^2 minima for 2008 season just for interest reasons and to plant my pole in the ice.

Do we have any other estimates?

Regards

Andy

314. TAC
Posted Aug 5, 2008 at 6:16 AM | Permalink

Jeez (#311),

Twenty-four long, grueling hours have passed and it is time to for that painful but necessary census of the unmelted—those last hardy remainders of the baby ice pod that still fights for its survival.

No sound is heard as the pod clusters together, communicating via touch who still lives and via absence those now wet souls who will be forever missed.

Seemingly sentient, the pod of baby ice stiffens, gaining resolve, bracing for the ongoing battle with the elements, and although it makes no sense, apparently leaning into the wind, as if gesturing, “bring it on!”

Is “March of the Baby Ice” scheduled for release?

315. Chris
Posted Aug 5, 2008 at 6:56 AM | Permalink

2008 still seems to be running 1990 respectably close:

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=05&fy=1990&sm=08&sd=04&sy=2008

316. Aaron Wells
Posted Aug 5, 2008 at 6:59 AM | Permalink

Thansk Aaron again for those graphs, is there a link for them in general so I do not have to keep asking?

You’re welcome. No, unfortunately I don’t have a personal web site to keep an updated version of the graphs. But now that we are getting into the final turn of the race, I will begin to post daily updates of my graphs after the morning revised data comes out.

317. ared
Posted Aug 5, 2008 at 7:34 AM | Permalink

#314, AndyW

My current estimate is between 5,0 and 5,8 with a best guesstimate of 5,3. My method is by looking at minimum, maximum and average extent loss for 2002-2007 between now and that year’s minimum, and then subtracting that number from the current extent. Unless something “unprecedented” (since 2002) happens, that should be in the ballpark.

318. steven mosher
Posted Aug 5, 2008 at 8:15 AM | Permalink

YOU GUYS ARE WATCHING ICE MELT. Get a life, watch cricket.

Just kidding. best of all I get to read jeez.

I meeting with Disney dude. So let’s get the pitch down

I’m thinking we use Sylvester Stallone for the voice of the baby ice

Or maybe Ice T…

Perhaps with some product placements by Nestee.

I’m seeing bags of baby ice in the supermarket.

I’m seeing Chivas on the baby ice.

I’m seeing a revival for vanilla Ice..

319. steven mosher
Posted Aug 5, 2008 at 8:19 AM | Permalink

320. Aaron Wells
Posted Aug 5, 2008 at 8:23 AM | Permalink

The final numbers for yesterday are in now, and the revised ice extent area was revised downward slightly, resulting in about 8 km^2 more area reduction than the preliminary amount. It is still the lowest amount of area reduction of all of the recent years for this date.

Here are my graphs based upon today’s final numbers:

Daily Sea Ice Extent Reduction Day 217

Sea Ice Extent Day 217

2008 Ice Extent Differences From Previous Years Day 217

321. MarkR
Posted Aug 5, 2008 at 8:37 AM | Permalink

Is it a Millyun yet? The Warmers like a Millyun.

322. John Lang
Posted Aug 5, 2008 at 9:11 AM | Permalink

I found a directory at the University of Colorado at Boulder linked to by the NSIDC which contains a lot of historical sea ice data.

This file, for example, has daily NH sea ice extent data from 1972 to 2002. Doesn’t quite match up with the current JAXA data but is close. Maybe the guys producing the daily melt rates could use another 30 years to come up with better averages.

Other historical sea ice extent databases are here.

Maybe someone could spend some time going through this huge database to find some better (and real-time) data.

Posted Aug 5, 2008 at 9:13 AM | Permalink

Jeez,

Seems like it’s getting a little heavy and morose for Disney. If you don’t snap out of it I think you may be headed for a Tim Burton movie instead.

For inspiration, think new Johnny Depp(Pirate) rather than old Johnny Depp (Scissorhands).

324. ared
Posted Aug 5, 2008 at 10:02 AM | Permalink

John Lang, it depends on what you call “close”. In the overlapping days in 2002, the average difference is 284000 km^2, ranging from almost +700.000 in June and December to -128000 in September. It seems the highs are much higher and the lows a bit lower. Using this data to finetune the IARC-JAXA based statistical models would probably earn us bragging rights at the Hockey Club.

Fine source of historical data nonetheless!

325. AndyW
Posted Aug 5, 2008 at 10:20 AM | Permalink

>YOU GUYS ARE WATCHING ICE MELT. Get a life, watch cricket.

Would that be the same cricket where they went from test matches being most popular to one day cricket to 20 overs and soon to be 1 over cricket?

Not a good track record for excitement if they keep having to reduce it ! :D

326. Jim Arndt
Posted Aug 5, 2008 at 10:32 AM | Permalink

Mosh

All you need is a Pinto with spinners and you will be pretty fly.

327. DeWitt Payne
Posted Aug 5, 2008 at 11:02 AM | Permalink

Big day at CT.

area difference anomaly
4.945 -0.172 -1.269

Might as well start tracking Antarctic sea ice as well, which had a big day too but in the opposite direction.

13.853 NA 0.045

That’s a big jump in the anomaly from -0.196 the day before. Looks like the pause is definitely over down south.

328. Fred Nieuwenhuis
Posted Aug 5, 2008 at 11:15 AM | Permalink

My \$0.02,

Rather than Kugluktuk, let’s take Alert (http://www.weatheroffice.gc.ca/city/pages/nu-22_metric_e.html), the northern most Canadian weather station. It’s “normal” daily mean temperture hits 0C on August 20th. Assuming that tempertures will follow the current “normal” downward trend (-0.2 C/day), as the week 2 ECWMF and GFS projections are indicating, time is running very short for any meaningful gains on 2007.

329. BarryW
Posted Aug 5, 2008 at 11:37 AM | Permalink

Re 330

Unless there is some dramatic change in the slope of the melt there doesn’t seem to be any way that 2008 will even get close to 2007. The question is will it pass 2006 and 2005 which are very close. Unless something happens today my prognostication of it passing 2006 today is blown. I guess one wild card is winds piling up the ice instead of just melt. Any info?

330. BarryW
Posted Aug 5, 2008 at 12:32 PM | Permalink

Re 319

YOU GUYS ARE WATCHING ICE MELT. Get a life, watch cricket.

This has a lot more action.

You need to do a product placement with Coke with the polar bears and seals. You can have the ice melt out from under the bear cub and the seal saves him and gives him a coke right before the seal is eaten by the bear’s mother.

331. tty
Posted Aug 5, 2008 at 2:26 PM | Permalink

Re Cricket

A swedish journalist once claimed that it was the only known team sport where both the audience and the players can have tea without interrupting the game.

332. TAC
Posted Aug 5, 2008 at 9:03 PM | Permalink

Preliminary Unofficial Day 218 Race Report
2008 has a big day with respect to everything except 2004.
8 6 2002 NA NA
8 6 2003 7.221250 -0.058906
8 5 2004 7.513125 -0.107813
8 6 2005 6.610469 -0.067969
8 6 2006 6.742500 -0.052500
8 6 2007 5.815156 -0.075313
8 5 2008 6.738125 -0.103438

333. BarryW
Posted Aug 5, 2008 at 9:21 PM | Permalink

Well, 2006 just got passed and has a low melt rate in the future. If 2008 stays this high….

334. DeWitt Payne
Posted Aug 5, 2008 at 9:34 PM | Permalink

2008 finally goes past 2006 a day or two sooner than expected.

Projected minimum drops to 5.38 Mm2 on 9/15. That’s still very close to the 2005 minimum of 5.31 Mm2. The rates of both are very close, but 2005 is in for a run of slow days in the next couple of weeks so the race is far from over. The smoothed loss rate for 2008 is still barely above the minimum set on 7/24. Two more 100,000 plus days will put the projected minimum below 2005.

335. BarryW
Posted Aug 5, 2008 at 9:35 PM | Permalink

Re 335

Steve: Not yet, but probably soon.

I meant passed going toward the minimum

2006 extent is 6.742500 which is just a tad higher than 6.738125 (2008) or do you have different numbers?

Steve:
Yep. So it did. Not a big surprise.

336. AndyW
Posted Aug 5, 2008 at 10:33 PM | Permalink

2008 has racking up quite a few 100k+ days, if it can hit one after the 8th that will be the latest one since the spreadsheet began, 2002. Which is interesting if not significant.

As the race against 2007 seems to be well and truly over it’s now a race for the silver medal position ( as we are in the Olympic frame of mind at present….)

337. DeWitt Payne
Posted Aug 5, 2008 at 11:03 PM | Permalink

Even the bronze is not yet clinched. 2008 could still potentially have a higher minimum than 2002. The 2002 minimum of 5.65 Mm2 is still well within even the 90% confidence limits.

338. jeez
Posted Aug 6, 2008 at 3:09 AM | Permalink

The long comfortable nights of the previous winter a distant, almost intangible memory, our familiar pod of baby ice continue to face setback upon setback.

Summer, earlier felt to be on the run, has returned with a spiteful vengeance this day to melt its terrible toll, to wither and consume again.

Scant energy left for diversion and play, the pod members’ instinct, alluded to previously, is all that stands between life and death, the solid phase, or the unspeakable.

Beaten down but not defeated the pod seeks safety in the currents, probing the elusive gyres, drifting in and out looking to find that subtle wisp of Coriolis that will take them home, to darkness, to rest.

339. Chris
Posted Aug 6, 2008 at 5:05 AM | Permalink

I wouldn’t be resigned to 2008 beating 2006 just yet.

Yes, 2006 has a much slower melt rate from now on, but not dramatically so for the time of year: its average melt rate for the next 14 days (6th-20th Aug) is -0.045 ((6.7425 – 6.116563) / 14)

It seems to be agreed that the sustained high melt rate in 2007 was caused by the persistence of very anomalously warm waters being pushed into the Arctic between Siberia and Alaska

That hasn’t occurred this year, indeed if anything the putative PDO shift has resulted in relatively colder waters on average in the strait

http://weather.unisys.com/surface/sst_anom.html

So it seems more likely that the relatively high melt rate of recent weeks has been caused by warm southerly winds coming from land and/or relatively cloud-free skies.

With regard to the winds, a little bit of research shows that there was indeed a sustained heatwave in northern Canada in the last month (caused by persistent southerlies) which fits the record Beaufort sea melt, and more recently there have been high temperatures in northern Siberia (again brought by persistent southerlies) which fit the recent melt north of the Siberian coast.
With regard to cloud-free skies, I have little knowledge, except for the fair assumption that the heatwaves have been associated with plenty of sunshine.

But the heatwave in northern Canada appears to have waned, and if anything the ice in the Beaufort sea closest to the strait appears to have grown back in the past week

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=07&fd=29&fy=2008&sm=08&sd=05&sy=2008

If the skies continue to be relatively cloud-free, this will increasingly have a negative effect on temperatures – c.f. Barrow in the next few days http://www.weatheronline.co.uk/cgi-bin/regframe?3CODE=%26WMO%3D70026%26PRG%3Dcitybild&LANG=en&PRG=citybild

It’s been hard for me to find info on pressure and temperature in the Arctic circle. But from what I can gather, there has been a fairly deep low north of Siberia in recent days which dragged up strong southerlies from the continent, presumably melting plenty of ice. But now that the sun is waning, any other type of wind will not be very effective to melt the ice, and even a weak southerly could lead to an overall drop in temperature with clear skies.

If you play about with the daily global temperature trends graphs from msu e.g. at 14,000 ft http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+002 with 2006 added (shame they can’t be broken down into regions) you will see that they tend to confirm my take on things. There was a peak towards the end of July which could most plausibly be caused by heatwaves over northern landmasses and associated warming over ocean surfaces immediately to their east (there has been little sign of warming in the southern hemisphere/tropics). But now 2008 temps appear to be on a definite downward trend just at the point where 2006 and 2007 temps were starting to climb to a second peak. (Note to those who would say global temperatures are irrelevant to the Arctic: they become increasingly relevant as we head away from summer, since the Arctic temperatures are increasingly dictated by heat transport from lower latitudes)

Of course, no one can predict what will happen. 2008 temps could easily go right up again in the next month, and a strong El Nino could set in to put even more warming into the pipeline.

But I wonder. Of course one more factor is the solar minimum, as the effects of UV variation on polar temperatures via stratospheric (i.e. mainly Ozone) cooling/warming is the one solar temperature signal that does not appear to be disputed. This signal certainly seems to have been a cooling one recently http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+010. I hasten to add, don’t read into this that I’m assuming solar variation is a major factor in the longer term! But it would be interesting if it helped tip the balance to the coming winter being even closer to the longer term global temperature average.

This has been a long post, hope it’s not been too tedious! Just a pointer to a couple of other things I’m interested in. Firstly, the idea that the higher albedo in the Antarctic, caused by recent positive sea ice anomalies, is twice as important as the lower albedo in the Arctic, caused by recent negative sea ice anomalies, because the average latitude of the ice margin in the Antarctic is much further from the pole (there’s a whole continent before you get to the sea ice) i.e. the sun is much stronger at the margin. Not to mention that the Arctic is largely cut off from the big oceans (think of current open Beaufort sea encircled by land/ice)
Secondly, the more speculative idea that there may be a link between Antarctic ice and La Nina. Looking at Antarctic ice over last year http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.south.jpg – I’m wondering, what happened to the “cold” last August if it didn’t stick around at the ice margin to freeze any ice, why does there seem to be a significant correlation between the sea ice extent and ENSO since then – see SOI graph at http://www.bom.gov.au/climate/enso/ – and what are the implications for the recent month of “cold” failing to translate into ice?

340. Flanagan
Posted Aug 6, 2008 at 8:21 AM | Permalink

As was already discussed before, the spatial pattern in 08 is quite close to the one in 04, for which the highest melting rates were observed between Aug 5 and Aug 15 (approximately). I guess that we’re going to have now quite high melt rates till the middle of next week, and that things should go slower after that. Seems difficult to imagine that 2007 can be beaten at that rate.

341. Aaron Wells
Posted Aug 6, 2008 at 9:01 AM | Permalink

The final numbers for yesterday are in now, and the revised ice extent area was revised downward significantly, resulting in about 14 km^2 more area reduction than the preliminary amount. The size of the downward revision today is almost as large as the total melt that will occur on tomorrows date in 2006, 17,345 km^2!

Here are my graphs based upon today’s final numbers:

Daily Sea Ice Extent Reduction Day 218

Sea Ice Extent Day 218

2008 Ice Extent Differences From Previous Years Day 218

342. Chris
Posted Aug 6, 2008 at 9:37 AM | Permalink

#341: I think 2008 is tracking 2003 more closely than 2004 (from analysis of temperature stats, but also c.f. Aaron’s second graph above in #342)

If I am correct, then we ought to see an imminent drastic slowdown in ice melt, which would be nice :) However, we have lots of “baby” ice, unlike in 2003/4, and also the revision to yesterday’s melt (as highlighted by Aaron) is not very encouraging…

Having set out my stall in #340 above, I will try to remember to return on 20th Aug, hopefully to confirm that the 2008 ice melt has stayed close to that of 2006, but if not to admit to over-optimism!

(N.b. my previous post (#29: “Hey guys don’t panic!…”) of 25th July seems to have been well founded – at that stage there was a worry that 2008 would catch 2007 after all because the melt rate appeared to be increasing significantly. But now we can see that 2008 is 0.91 million km/2 behind 2007 on 5th Aug, exactly the same as on 24th Jul. Of course, maybe it was just luck and I won’t be so lucky this time!)

Hang on in there baby ice :)

343. Posted Aug 6, 2008 at 9:43 AM | Permalink

Re #341

As was already discussed before, the spatial pattern in 08 is quite close to the one in 04

Really I don’t see that?
08 vs 04 comparison

344. Kenneth Fritsch
Posted Aug 6, 2008 at 10:23 AM | Permalink

I must admit that I come daily to this thread almost exclusively to hear the epic travails of baby ice as rendered by jeez. Baby ice has been made endearing, if not enduring, and I think, though not yet described, I can hear some sympathetic sounds coming from those baby ices that my limited imagination cannot put into words.

345. Barney Frank
Posted Aug 6, 2008 at 10:57 AM | Permalink

Do the canucks still club baby ices every spring?
And if so could that be contributing to the early breakup?

346. RomanM
Posted Aug 6, 2008 at 11:09 AM | Permalink

No, they stopped clubbing them so the the baby ices could fulfill their dream of growing up to be full fledged ice rinks used by the Hockey Team!

347. Posted Aug 6, 2008 at 12:01 PM | Permalink

Re #329

Big day at CT.

area difference anomaly
4.945 -0.172 -1.269

Followed by another:

4.630 -0.315 -1.481

Change appears mostly in the Arctic basin.

348. crosspatch
Posted Aug 6, 2008 at 12:46 PM | Permalink

343: “also the revision to yesterday’s melt”

Again, please do not mistake a reduction in ice coverage for “melt”. It could be that wind patterns changed and bunched the ice up more someplace and caused there to be more open ocean surface with very little change in the actual amount of ice.

Lets say you have a region where 25% of the sea surface is covered with chunks of ice, not a solid sheet, but floating chunks. That entire region would be listed as “ice”. Now the wind comes up and bunches all those floating chunks together and suddenly the region is showing “ice free” when there really was little or no change in the amount of ice volume.

349. Posted Aug 6, 2008 at 1:22 PM | Permalink

Jeez posts on the baby ice are definitely terrific!

350. Sam Urbinto
Posted Aug 6, 2008 at 1:47 PM | Permalink

350 crosspatch

Now the wind comes up and bunches all those floating chunks together and suddenly the region is showing “ice free” when there really was little or no change in the amount of ice volume.

That doesn’t fit the narative.

351. Posted Aug 6, 2008 at 2:04 PM | Permalink

Re #350

That’s why it’s a good idea to watch both extent and total area (as followed by Cryosphere Today), area should be independent of compaction by the wind unless the ice starts stacking up. The AMSR product has a 3xhigher resolution though and therefore the rate progression might be smoother as a result.

352. bender
Posted Aug 6, 2008 at 3:41 PM | Permalink

#349

Followed by another

Imagine that – melting as an autocorrelated weather process. Maybe climate has similar low-frequency behavior? Maybe deep ocean circulation? Just a whacky pet theory.

353. markinaustin
Posted Aug 6, 2008 at 3:43 PM | Permalink

chris, great post! one question. according to that same page: “During global warming, the atmosphere near the surface is supposed to warm at least as fast as the surface warms, while the upper layers are supposed to cool much faster than the surface warms.”

does this not mean that the altitude you showed to be cooling actually is evidence of Global Warming?

i am a huge skeptic by the way, but trying to understand the terms nonetheless.

354. Sam Urbinto
Posted Aug 6, 2008 at 3:52 PM | Permalink

The idea as I understand it is that if the Earth is absorbing more energy due to elevated levels of non-water greenhouse gases, the additional energy will be transfered out at a different level, due to the lapse rate; lower pressure higher up basically; and that signal should be able to be seen. I forget if we’re supposed to ignore the energy content of the liquid parts of the surface, or the solid parts to some depth or another.

It all seems rather wacky; like trying to count how many leaves there are on the Earth’s plants. But that’s just me I suppose.

355. D. Patterson
Posted Aug 6, 2008 at 5:32 PM | Permalink

356 Sam Urbinto says:

August 6th, 2008 at 3:52 pm
The idea as I understand it is that if the Earth is absorbing more energy due to elevated levels of non-water greenhouse gases, the additional energy will be transfered out at a different level, due to the lapse rate; lower pressure higher up basically; and that signal should be able to be seen. I forget if we’re supposed to ignore the energy content of the liquid parts of the surface, or the solid parts to some depth or another.

It all seems rather wacky; like trying to count how many leaves there are on the Earth’s plants. But that’s just me I suppose.

Increased surface temperatures increases precipitation rates. Increased precipitation rates increases freshwater runoff into the seas. Increased runoff of freshwater into the seas changes water temperatures at various depths, changes salinity, alters oceanic circulation patterns, alters upwelling and downwelling of oceanic circulation, and the changed oceanic circulation patterns alters the capture and release rates of cryospheric and atmospheric thermal energies. So, the other energy capacities comprising the vast majority of the thermal heat storage of the planet cannot be neglected.

356. BarryW
Posted Aug 6, 2008 at 8:54 PM | Permalink

It looks like 8 5 2008 melt was adjusted up:

Last 6.738125 -0.103438
Now 6.724844 -0.116719

357. Steve McIntyre
Posted Aug 6, 2008 at 9:13 PM | Permalink

A huge day for 2008. By far the biggest of the year. Blew right by 2006 and is on the heels of 2005.

month day year ice diff
8 7 2002 6.964 -0.08137
8 7 2003 7.149 -0.07203
8 6 2004 7.424 -0.08906
8 7 2005 6.553 -0.05797
8 7 2006 6.725 -0.01734
8 7 2007 5.725 -0.09047
8 6 2008 6.582 -0.14250

358. jeez
Posted Aug 6, 2008 at 9:31 PM | Permalink

It was another tragic day for the baby ice pod, for summer, nature’s crucible, is relentless, giving no pause, no safe harbor for the baby ice to find sanctuary.

The pod’s leader, the alpha block, has become incapacitated, barely bobbing above the liquid surface. He is unlikely to recover before it’s too late.

The survivors spread out to mourn his passing in advance for they have seen this pattern unfold too many times to cling to false hopes.

Later, during the short night, they must come together as one to select a new alpha.

359. jae
Posted Aug 6, 2008 at 9:34 PM | Permalink

jeez: does that mean the polar bear cub is lost forever?

360. Steve McIntyre
Posted Aug 6, 2008 at 9:39 PM | Permalink

I’ve done a big scrape of NSIDC binary data (it took nearly a working day) and calculated daily areas and extents, as best as I can understand the definitions – I am unable to locate any explicit algorithm. The data frame has information on date, julian day, area, extent and “hole” size (a change occurs in 1986-87.) You can get this information as yourself (about 250 K)as follows:

dim(Arctic) # 10866 12

IF you want to do your own update, load the data frame and then do this:

source(“http://data.climateaudit.org/scripts/seaice/functions.seaice.txt”)
Arctic=update.nsidc()

THis downloads the f15 satellite. Two satellites are currently reporting f13 and f15 (results differ). JAXA extent differs from these results, which I don’t guarantee, tho the shapes look sensible. HEre’s a plot of extent and area in recent years. Oddly, for these numbers, 2008 area is higher than 2007, but, unlike JAXA, extent is running in tandem. (The JAXA 2008 extent is plotted in the dashed line in the middle.) If anyone can sort the various definitions, I’d appreciate it.

361. Posted Aug 6, 2008 at 9:49 PM | Permalink

Re #358
A big melt day today for extent as well as area:

8/5/2008 6.724844 -0.116719
8/6/2008 6.582344 -0.142500

362. DeWitt Payne
Posted Aug 6, 2008 at 10:02 PM | Permalink

The projected minimum extent is now 5.29 Mm2 on 9/14. That’s below 2005 but still well above 2007. The smoothed loss rate for 2008 set a new low of -0.090 Mm2/day, lower than 2007 at the same time and lower than any year other than 2007, so we haven’t even turned the corner yet. 2004 and 2006 are right at the 90% upper confidence limit, leaving only 2002 at 5.65 Mm2 and 2005 at 5.31 Mm2 still in the running. We are only 4 days away from possibly setting a new record for latest date of maximum extent loss set on 8/10/2004.

363. Steve McIntyre
Posted Aug 6, 2008 at 10:24 PM | Permalink

Area seems to bottom out earlier than extent – I wonder why.

364. Daryl M
Posted Aug 6, 2008 at 11:14 PM | Permalink

Re #365

A possible explanation is that the ice floes stop melting before they stop drifting around.

365. Posted Aug 6, 2008 at 11:23 PM | Permalink

Re #362
Steve, seems a bit strange I would have thought if you are using the wrong trig transformation that the difference would at least be systematic but your 2008 curve has the lowest max whereas it should be the highest of the set, if you just sum pixels surely winter 07/8 has the most pixels?
I’m assuming that the data was trig transformed, I know that it’s possible to import the data in different projections, which transformation are you using?

The Spreen et al. paper implies that pixel size is constant at 19 km^2, in which case extent should be Sum (pixels greater than 0.15*19) and the area be the same terms *conc? Presumably that’s not the data format you’ve downloaded?

366. See - owe to Rich
Posted Aug 7, 2008 at 1:28 AM | Permalink

Alone, afraid, and aweful, baby ice lies sadly wilting, wilting against the ravages of the harsh August Sun. That star, once a seeming friend in the distant days of Spring, is now the uncompromising enemy.

So little time. Yet even as baby ice ebbs and floes off towards that final sunset, dim memories of happy days and favourite movies surface. Sweet thoughts of succour. Sinking into that trancelike state, baby ice dreams of the U.S. Cavalry, of Superman, and of that immortal line “Hey don’t stop, Bagheerajeez, there’s more, much more!”

367. See - owe to Rich
Posted Aug 7, 2008 at 1:32 AM | Permalink

Sorry. I won’t do that again, but it came to me in the middle of the night.

I’ll quit the floor for the master now.

Rich, alias PlagiaristsRUS

368. AndyW
Posted Aug 7, 2008 at 1:47 AM | Permalink

For the first 6 days of August 2008 shows, by a large margin, an amount of melt greater compared to any other year in the small range of the spreadsheet. Assuming the weather is typical or slightly better this year then you could say that the young ice is finally having an effect and extending the main melt season towards later in the year. This sort of tallies with the mid year appraisal of the scientists who said the younger ice was actually thicker than they expected due to lack of snow cover at the backend of last year. It nows seems to be finally getting the chop. Probably be 20 000 tomorrow having said that though.

Looking at Steve’s graphs above it looks suspiciously like the JAXA values are an average of extent and area, but that might just be a visual effect I guess. Thinking about area and extent it would seem that area is by far the better measure, but I guess it lows better historical tally using extent. The interesting thing to me is how a relatively large extent but smaller area re-freezes this winter. Will it re-freeze in the standard way or be different. I might be perpetually watching this forever now.

As for ice not being exciting to watch, well at least you can see it, unlike CO2 (apologies to CO2 enthusiasts out there). I must confess to having a slight “Holy Moly” outburst when seeing the latest figure. Not a big one I hasten to add, I do not want to be thought to be some sort of solid water pervert. The size of the comments list for Steve’s entries show the interest though…..

369. Chris
Posted Aug 7, 2008 at 3:05 AM | Permalink

Hey guys don’t panic :)

Just thought I’d stick my neck out a bit further and add some more optimism. Ok the last day’s melt has made it very much less likely that 2008 will be close to 2006 in 2 weeks time.

But everything happens for a reason, and I can’t see any evidence that the main reason for the sudden high melt rate is the thinness of the ice, since otherwise we would have seen this a long time before now.

The best reason I can see for the current high melt rate is the low pressure I mentioned previously http://weather.uwyo.edu/cgi-bin/uamap?REGION=np&OUTPUT=gif&TYPE=obs&TYPE=an&LEVEL=500&TIME=2008080700 (generated from http://weather.uwyo.edu/upperair/uamap.html) dragging warm southerlies up into the Siberian seas.

If you look at how where the ice has melted in the last 3 days http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=03&fy=2008&sm=08&sd=06&sy=2008 this appears to be confirmed.

Now the reason for my continued optimism (or at least lack of panic) can be understood if you now compare the image for today with the same day in 2006 – http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=07&fy=2006&sm=08&sd=06&sy=2008 The most plausible areas for significant further 2008 melt would appear to be Beaufort sea (or rather, the part of the Arctic Basin it adjoins, using CT categorisation), Chuckchi, East Siberian and Laptev seas (from top left to top right).

The Beaufort/Arctic Basin seems least likely to melt much further because (1) the melt appears to have slowing rather than accelerating there in recent days, (2) the weather appears to be cold there from what I can gather, (3) the ice boundary there is much further north than in 2006, so the sun should be proportionately weaker

So it is the other seas which are critical. In the East Siberian/Laptev seas it looks as if recent warm southerly winds have quickly melted a lot of the (thinner) ice within a few hundred km of the coast, and also blown a lot of it around (the significance of this is hard to judge). But the crucial point to bear in mind is that the ice at the boundary appears more concentrated than it was in 2006. Thus, it again seems more likely that the current high melt rate is temporary, and once weather patterns change, if anything the melt rate should be slower there than in 2006.

That leaves the Chuckchi sea. Here I’m just not sure: there may be conflicting factors at work. The concentration has thinned in recent days, but in some parts the extent has increased. On the east side the sea seems anomalously cold but on the west side it seems warm. It seems possible that the winds from Siberia has blown some of its ice into warmer waters near the strait to melt. Unfortunately I think there is the potential here for further significant melt, as there is now a lot of low concentration ice.

I think a lot depends on how the weather patterns develop, and despite a big googling effort I’ve been unable to find synoptic forecasts for the relevant areas – I don’t know if anyone could help with this?

So my optimism is that the melt rate should soon be back in line with earlier years. It’s just unfortunate that until that happens each day is likely to keep bringing huge melt figures…..
I’m so annoyed that I had to return after the first day of my 2-week holiday from ice watching!!! The suspense is killing me…..

#355: this is obviously a very complicated issue, and goes to the heart of the AGW debate. But the simple answer is that both the surface AND the stratosphere appear to have got colder in recent years

By the way, for what it’s worth the msu data show global lower troposphere temperatures continuing to fall by 0.13F yesterday over the day before, compared with a rise of 0.02F in 2007 and 0.00F in 2006 http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+002

370. Chris
Posted Aug 7, 2008 at 3:42 AM | Permalink

Anecdotal evidence of retreat of Arctic summer:

Couldn’t resist adding one further link. I know it could be seen as “cherry picking” but I find it interesting to note that temperatures at Greenland Summit Camp have dipped back under -20C after the late July peak.

http://www.summitcamp.org/transport/weatherstation/mainpage.py?view=Month

371. BarryW
Posted Aug 7, 2008 at 5:43 AM | Permalink

A couple of days from now it looks like the melt rates for all the previous years are going to drop significantly. If 2007 sustained yesterday’s rate it would only take 16 days to beat 2007. Not likely but if it doesn’t get back with the pack soon it’s going to easily get second place and still might beat 2007.

372. Chris
Posted Aug 7, 2008 at 6:36 AM | Permalink

Still looking grim for Siberia though….
Here’s the forecast for Tiksi on the Laptev coast:

http://www.wunderground.com/global/stations/21824.html

(peaking at 21C max/13C min on Sat, then again at 21C max/13C min on Wed, at which point wind forecast to be 10km/h from SSW increasing to 14km/h from SW overnight… )
If only Tiksi’s weather was closer to the “baby ice sanctuary” conditions in Alert in the extreme north of Canada: http://www.wunderground.com/global/stations/71082.html

373. Chris
Posted Aug 7, 2008 at 6:52 AM | Permalink

Even worse, current weather in Tiksi (local time 10.37pm) is 15C with winds *32KM/H* from the SSE, after what must have been a fairly hot day. The winds are likely to have been making the Laptev seas very choppy, giving the baby ice a rough ride, and in turn the choppier the sea surface, the more friction the warm winds are likely to have been generating, speeding further the warming of the seas and melting of the ice. It’s as if a callous god has thrown the baby ice into the washing machine on warm cycle :(
How many more agonising days will it be before the vortex of doom finally spins itself away from the Siberian seas?
Deep low pressure area in Siberian seas – http://weather.uwyo.edu/cgi-bin/uamap?REGION=np&OUTPUT=gif&TYPE=obs&TYPE=an&LEVEL=500&TIME=2008080700
Laptev weather – http://www.wunderground.com/global/stations/21824.html

374. AndyW
Posted Aug 7, 2008 at 6:58 AM | Permalink

>The best reason I can see for the current high melt rate is the low pressure I mentioned previously

Hi Chris,

I don’t understand how one LOW can cause an increase, surely lows make increases less likely, or are you saying that the higher winds associates with it reduced the extent as it blew the ice back together? Condsidering yesterdays was one of the bigger melts in August all told I think that more shows the state of the ice than any transient localised weather patter,

We’ll know in a few days though, I favour large melts for the near future, you suspect low melts in the next week or so. Will be easy to spot who’s correct of course.

375. AndyW
Posted Aug 7, 2008 at 6:59 AM | Permalink

I really ought to spell check my posts ..sigh.

376. Chris
Posted Aug 7, 2008 at 7:06 AM | Permalink

Just for precision, I should note that the low pressure itself is centered between Arctic Basin/Kara and Barents Seas, it’s just that it’s at the Siberian coasts that the south/southwesterly winds are being funnelled up into the Arctic Circle, and thus over the Siberian seas (with existing open water) that there is maximum impact.

377. Chris
Posted Aug 7, 2008 at 7:34 AM | Permalink

#376 “I don’t understand how one LOW can cause an increase” – consider the spin cycle analogy in #375. Warmer water is the main thing that melts ice (c.f. the generally accepted explanation for record summer melt in 2007) and this is either going to come from the side (edge of ice extent/edges of individual ice floes) or from below i.e. the water the ice is floating on. The low pressure will have generated waves/chop in the Siberian seas (this wouldn’t have been possible until recently as they were largely frozen all the way to the coast). This will have increased the friction of the water on the ice at the “edges” thereby melting it much more quickly. But remember also that there are large areas where the sea surface is a mixture of water and ice. In these areas the waves/chop will generate significantly more friction between the ice and the water underneath, as well. So those are the indirect effects of the winds. But also, more waves/chop means more surface area, which mean the direct warming effects of the winds are larger as well. Not to mention any rains that the low pressure might have brought.
If I was baby ice, I’d much prefer to face high pressure with waning sun, maximum radiation escaping to space, minimum reflected radiation, and calm conditions bringing minimal friction with water or air.

378. Chris
Posted Aug 7, 2008 at 7:46 AM | Permalink

#376 “We’ll know in a few days though, I favour large melts for the near future, you suspect low melts in the next week or so. Will be easy to spot who’s correct of course.”

– To be precise I now also favour large melts for the near future i.e. as long as conditions continue to favour very high melt rates in the Siberian seas (as I noted in #374/375 i.e. up to a week, hopefully not more…) My previous confidence in the short term was based on an assumption that the weather pattern couldn’t last (for want of more information) but now I’m not so sure…
– But once conditions change I do suspect that melts will turn sharply lower.
So we might both be correct. Of course I hope we’re both wrong and melt rates slow to practically zero as of today :)

379. Aaron Wells
Posted Aug 7, 2008 at 8:26 AM | Permalink

The revised morning numbers are in, and again there was a downward revision (only about 4 km^2 this time) of the ice extent area.

Here are my graphs. CAUTION!!! They are not pretty! (Baby ice being slaughtered in wholesale numbers!) It’s like a train wreck. You rubber-necking gawkers just move along!

Daily Sea Ice Extent Reduction Day 219

Sea Ice Extent Day 219

2008 Ice Extent Differences From Previous Years Day 219

380. UK John
Posted Aug 7, 2008 at 9:35 AM | Permalink

I do hope the baby ice makes it, if not Phil will be even more unbearable

381. UK John
Posted Aug 7, 2008 at 9:49 AM | Permalink

#362 Definitions for ice extent, area etc and trying to find algorithms.

I have trod this path last year Steve but not being as focussed as you gave up at the first non reply for a link to algorithm at NSIDC. Found the definitions, that bit was easy.

Probably couldn’t have done much with the algorithm even if they gave it me ! They did have problems last year when it all went horribly wrong when they changed computers, and the figures disappeared for a few weeks.

Tried the UK Met office as they seem happy to quote figures all the time, but after a bit of correspondence I reached the view that I probably knew more than them.

Best of luck!

382. Chris
Posted Aug 7, 2008 at 9:57 AM | Permalink

Very last thing…..

I forgot to point out in #379 above that the weather pattern concerned does not exclude plenty of sunshine over the Siberian seas/ice, on top of everything else.

#381 Aaron – thanks for the graphs, and the warning about the dire contents….

Btw in case anyone thinks I was posting in the middle of the night earlier, I live in the UK so several hours ahead of many of you…. In fact I’m right in the heart of Central England, where the Temperature record has been very interesting….but that’s a whole different subject…..

Anyway, I’ll shut up now, as I’ve been posting way more than my fair share – it’s time for me to get back to that 2 week break from ice watching!!

383. DeWitt Payne
Posted Aug 7, 2008 at 10:18 AM | Permalink

Ice areas from CT
Arctic
area difference anomaly
4.532 -0.098 -1.522

Antarctic
13.767 -0.089 -0.094

If this rate continues in the Arctic, the area on 8/9/2008 will be very close to the 4.0 reported on the same day (8/10/2007) last year. Note the loss in area in the Antarctic. Unless there is an increase in rate real soon, area in the Antarctic will be far below last year’s record.

384. Sam Urbinto
Posted Aug 7, 2008 at 11:25 AM | Permalink

357 D. Patterson

Increased surface temperatures increases precipitation rates. Increased precipitation rates increases freshwater runoff into the seas. Increased runoff of freshwater into the seas changes water temperatures at various depths, changes salinity, alters oceanic circulation patterns, alters upwelling and downwelling of oceanic circulation, and the changed oceanic circulation patterns alters the capture and release rates of cryospheric and atmospheric thermal energies. So, the other energy capacities comprising the vast majority of the thermal heat storage of the planet cannot be neglected.

Well phrased. That’s part what I’ve been babbling about so often; you simply have to include the hydrosphere’s role in climate. I’m sure it is 99% of what’s happening, relegating carbon dioxide and its equivalents to perhaps .5% of whatever rise in energy budget is happening.

But where is the discussion on energy levels? One would imagine if one was concerned about how exactly (which appears unknown) humans are changing the climate (of which there is little doubt) that person would be interested in energy levels rather than proxy data; samples of the land by point measurements of the air and samples of water in shipping lanes. Mayhaps more attention would be paid to the satellites measuring radiance levels. I don’t know.

This is interesting. From http://en.wikipedia.org/wiki/Earth%27s_energy_budget

30% of the incident energy is reflected, consisting of:
6% reflected from the atmosphere
20% reflected from clouds
4% reflected from the ground (including land, water and ice)

The remaining 70% of the incident energy is absorbed:

A. 51% absorbed by land and water, then emerging in the following ways: 1) 23% transferred back into the atmosphere as latent heat by the evaporation of water, called latent heat flux 2) 7% transferred back into the atmosphere by heated rising air, called Sensible heat flux 3) 6%

B: 19% absorbed by the atmosphere and clouds, including 1) 16% reradiated back into space
2) 3% transferred to clouds, from where it is radiated back into space

When the Earth is at thermal equilibrium, the same 70% that is absorbed is reradiated:
64% by the clouds and atmosphere
6% by the ground

The largest and best-known are from the well-mixed greenhouse gases (CO2, CH4, halocarbons, etc.), totalling an increase in forcing of 2.4 W m-2 relative to 1750. This is less than 1% of the solar input,

So where’s the role of a gas known (according to AR4) to be only about 2/3rds of only the forcing aspect of only the long-lived greenhouse gases?

I would contend that if carbon dioxide emissions were totally halted right this second, there would be no effect upon the anomaly whatsoever. For whatever period of time you want to consider. I can’t prove it, but nobody can disprove it either. So it’s rather moot. Just like how much sea ice there is in the Arctic or if it’s going up or down.

Although it is interesting. :)

385. BarryW
Posted Aug 7, 2008 at 12:05 PM | Permalink

Oh the humanity! Where are the Hollywood celebrities and limousine liberals now that the baby ice is being slaughtered? Where’s Michael Moore’s documentary? The world must know of this tragedy before it’s too late! Shave, uh I mean Save the Baby Ice!

386. D. Patterson
Posted Aug 7, 2008 at 2:44 PM | Permalink

AndyW says:
August 7th, 2008 at 6:58 am
>The best reason I can see for the current high melt rate is the low pressure I mentioned previously
Hi Chris,
I don’t understand how one LOW can cause an increase, surely lows make increases less likely

The increased precipitation associated with a low pressure system can increase freshwater into the sea directly and from land surface runoff. The freshwater lowers salinity in various depths of those seas affected by oceanic currents carrying the freshwater fractions. The Arctic ice canopy is partially shielded from warm waters by a halocline, which is the stratification of the water due to salinity. Oceanic currents carrying increased freshwater fractions weaken and disrupt the halocline or salinity layers which otherwise maintain cold water in contact with the ice canopy and warmer water below. Consequently, a low pressure area along the margins of the Arctic may cause precipitation and freshwater currents that weaken the strong thermal stratification of the Arctic seawater and thereby bring warmer water into contact with the base of the ice canopy.

387. Sam Urbinto
Posted Aug 7, 2008 at 3:13 PM | Permalink

Yeah, warmer water makes ice above it melt. :)

388. Chris
Posted Aug 7, 2008 at 3:18 PM | Permalink

Had one more review of the indicators I have for weather developments in the Siberian seas (if I could find detailed synoptic charts/forecasts for the area it would be so much easier.) Looking at http://www.opc.ncep.noaa.gov/Loops/UA_Entire/UA_Entire_03_Day.shtml which gives the last 3 days in the northern hemisphere, it seems the low has now run its course and faded. As for the weather forecast for Tiksi on the Laptev coast, I just looked at weatheronline, which I normally use and find to be accurate http://www.weatheronline.co.uk/RussianFeder/Tiksi.htm and if you click on “wind” you can see there is no sign of southerlies continuing after all.
I’m therefore confident again that the melt rate will slow dramatically very soon.
It’s been a long day…..

389. Chris
Posted Aug 7, 2008 at 3:31 PM | Permalink

By the way when I referred to friction before, perhaps I should have spelt out more clearly what I meant. Quite simply (in layman’s terms), if the ice/surrounding water are still, the water closest to the ice will be only fractionally warmer (think of it as being cooled by the ice) and will not melt it very much, whereas if there is turbulence then the water which comes into contact with the ice will be warmer and continually replaced (against the surface of the ice) by the turbulence. (In #388 D.Patterson refers in more technical terms to how this works in the context of salinity)

390. DeWitt Payne
Posted Aug 7, 2008 at 4:03 PM | Permalink

Chris,

In other words, convection transfers heat faster than conduction in a medium with high heat capacity but relatively low thermal conductivity. Radiation is not a factor because the temperature difference is too low.

391. BarryW
Posted Aug 7, 2008 at 9:12 PM | Permalink

The Baby Ice just passed 2005. 6.513906 (2005) vs 6.477344 (2006) 11pm EST

392. DeWitt Payne
Posted Aug 7, 2008 at 9:58 PM | Permalink

Projected extent minimum down to 5.27 Mm2 on 9/14. 2004 and 2006 are out of the running at the 90% confidence level. That leaves just 2002 at 5.65 Mm2 (also close to elimination) and 2005 at 5.32 Mm2. 2007 will look like it’s building a big lead on 2005 for the next few weeks, but 2005 has a long period of about constant extent loss for about two weeks near the end of the season as well as a minimum extent date at 9/21 almost as late as 2007. Same day comparison may be misleading. That presumes that 2008 does indeed have it’s minimum extent on 9/14.

393. AndyW
Posted Aug 8, 2008 at 1:06 AM | Permalink

Thanks to Chris et al. for the thoughts on Low pressure areas on the effect of ice amount. I’m not totally convinced however as I would have thought the amount of melting due to warmer SW winds and low salt water would be offset by precipitation putting a layer of snow down and lack of solar melting.

We shall see now as it seems to have bug***d off ( I am from the UK too Chris, SE England :) ) so in theory it should now decrease.

394. D. Patterson
Posted Aug 8, 2008 at 1:22 AM | Permalink

Readers may find this to be an interesting paper on the subject:

Boyd, T., M. Steele, R.D. Muench and J.T. Gunn, 2002. Partial recovery of the Arctic Ocean halocline, Geophys. Res. Lett.

395. TAC
Posted Aug 8, 2008 at 2:27 AM | Permalink

Preliminary Unofficial Day 220 Race Report
2008 has another big day, and has now passed 2005.
8 8 2002 NA NA
8 8 2003 7.032031 -0.117188
8 7 2004 7.308594 -0.115469
8 8 2005 6.513906 -0.038594
8 8 2006 6.689063 -0.036093
8 8 2007 5.649063 -0.075625
8 7 2008 6.477344 -0.102500

396. STAFFAN LINDSTROEM
Posted Aug 8, 2008 at 3:03 AM | Permalink

do the googledance…Another reference paper is Dorn et al:
“The recent decline of arctic summer ice…”
In referring to a Zhang et al paper which, Dorn et al concludes that
2007 was probably an anomaly, an outlier…CMIIWH Read on folks!!
Looking for more…

397. been drinking since 12:30 pm PDT cuz mosh was in town jeez
Posted Aug 8, 2008 at 3:44 AM | Permalink

The baby ice pod’s new alpha, selected unambiguously during the cool, sweet, but ephemeral night quickly rises to the call and takes stock of the current situation.

Survival of the pod during this unprecedentedly grueling span of torment is not the only concern, for the unthinkable must now be thought, survival of the baby ice species may be at stake.

What strategies must the young alpha forge for the vestigial remnants of the pod? What cruel twist of fate was it that he above all others was chosen for this responsibility, with little or no time to prepare?

Undaunted by the most daunting of tasks, the new alpha communicates his plans to the receptive pod, as they close ranks, to behave as one, one block, one goal.

398. Chris
Posted Aug 8, 2008 at 4:15 AM | Permalink

#395 Cheers, Andy…

But it’s vital to point out here that people shouldn’t get distracted by salinity, it’s simply a minimal factor in the short term in relation to the effects of warm winds/water turbulence on ice (see in particular #379/#391 above) As for snow, you can bet the southerlies concerned will have brought precious little of this (we’re talking consistent 15C surface temp here), and even if there was a tiny bit on the leading edge of the first front to push through it will hardly have frozen the sea. I can’t see that that there is any room for doubt on these points…..

As for solar melting, as far as I can tell the winds are likely to have brought plenty of sunshine with them – just like the warm southerlies/southeasterlies which incidentally heated the seas significantly around the UK at the end of July.

(But it was a LOW you’re thinking? Remember, the centre of the low was hundreds of miles to the west of the Siberian seas, and the winds were carried off a large and by definition dry continent. If you’re still not convinced that the low brought warm temperatures and sunshine, how can you explain the max temps of 22C and 24C in Tiksi on Mon and Tue respectively?)

I’ve been determined to nail these points (and hence have kept returning to post one last time!) because I’m sure significant short-term variations (i.e. in ice extent reduction) are likely to have significant short-term causes, and the obvious short-term cause is the low pressure system.

399. Chris
Posted Aug 8, 2008 at 4:26 AM | Permalink

By the way I keep forgetting to mention that I too am a massive fan of Jeez’s baby ice updates!!!!!!!

400. Chris
Posted Aug 8, 2008 at 5:12 AM | Permalink

#400 “If you’re still not convinced that the low brought warm temperatures and sunshine, how can you explain the max temps of 22C and 24C in Tiksi on Mon and Tue respectively?”
To make it crystal clear, I meant Mon and Tue earlier this week i.e. 4th and 5th Aug (you can check this by going to http://www.weatheronline.co.uk/RussianFeder/Tiksi.htm and clicking on “History”)

[Just to pre-empt anyone who spots the warm forecasts for next Wed/Thu, the facts that (i) the winds are to be W/SW rather than SE/S and (ii) the ice E/NE of Tiksi is now largely gone, mean that the forecasts do not necessarily imply anything like a repeat of the last couple of days]

401. D. Patterson
Posted Aug 8, 2008 at 5:46 AM | Permalink

398 STAFFAN LINDSTROEM says:
August 8th, 2008 at 3:03 am

Yes, I had a number of such links to various related papers, but the posts were killed. So, I just posted the Boyd et al reference to provide at least one lead on the general subject. There is quite a bit of literature in the past decade and currently in press which is based upon some very interesting discoveries from the SCICEX expeditions in the Arctic. There is everything from the empirical research to the latest in oceanic modeling. Note in particular the papers from APLUW in 2008 and earlier.

402. Mike Bryant
Posted Aug 8, 2008 at 6:26 AM | Permalink

2008 is almost mid distance between 2004 and 2007. Trend doesn’t look good. GO BABY ICE!!!

403. Chris
Posted Aug 8, 2008 at 8:26 AM | Permalink

Latest MSU data appear to show summer 2008 so far for North Pole (average of June and July temperature anomalies) to be the coldest since 2000 – interesting for the summer when many was suggested it would melt completely sending it via albedo into dangerous positive feedback…. (Though also note still some way to fall to reach pre-1998 average.)
Please note the following figures are preliminary/unofficial as I’ve just calculated them very quickly:

June/July average temperature anomaly:
1988 0.45
1989 -0.02
1990 0.24
1991 0.56
1992 -0.89
1993 0.26
1994 0.06
1995 0.22
1996 -0.60
1997 0.19
1998 0.64
1999 0.46
2000 0.27
2001 0.68
2002 0.79
2003 0.85
2004 0.53
2005 1.04
2006 0.83
2007 1.47
2008 0.52

Raw MSU data is here: http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt

Posted Aug 8, 2008 at 8:26 AM | Permalink

I have “Go Baby Ice!” bumper stickers available and am now accepting celebrity nominations to host a Baby Ice telethon.

405. BarryW
Posted Aug 8, 2008 at 8:33 AM | Permalink

July melt has been revised upward to -0.094219

406. Chris
Posted Aug 8, 2008 at 8:45 AM | Permalink

Thanks BarryW. Just to clarify, yesterday’s reduction in ice extent has been revised from -0.102500 to -0.094219. I await tomorrow’s figures with bated breath…………………

407. Aaron Wells
Posted Aug 8, 2008 at 9:08 AM | Permalink

As BarryW mentioned, the final numbers for yesterday’s extent area reduction revised the extent area upwards by about 8 km^2, leaving the final reduction for yesterday at 94,219 km^2. Still a large area reduction, but compared to 2004 and 2003, it is not so bad:

2003 117,189
2004 115,470

Plus, both of these years are going to have a pretty big day for tomorrow’s date:

2003 99,219
2004 108,751

So, things aren’t quite as bleak for the baby ice as it seemed a day or 2 ago.

Here are my graphs for yesterday’s ice extent data. Go Baby Ice!

Daily Arctic Sea Ice Extent Reduction Day 220

Arctic Sea Ice Extent Day 220

2008 Arctic Ice Extent Differences From Previous Years Day 220

408. BarryW
Posted Aug 8, 2008 at 9:51 AM | Permalink

Aaron

If I didn’t screw up the averaging (or my dates) , the average melt for 2003-2007 for tomorrow should be about 75,000 while 2005/6 are going to be down around 50,000. The average melt rate is going to drop significantly after that to about 50,000 and continue dropping. 2008 is going to have to come up significantly to catch the pack.

409. DeWitt Payne
Posted Aug 8, 2008 at 10:42 AM | Permalink

CT ice area update:
Extent difference anomaly
Arctic
4.375 -0.157 -1.637
Antarctic
13.749 -0.018 -0.129

If tomorrow and the next day are -100,000 km2 days in the Arctic, 2008 will be less than 200,000 km2 above 2007 on the same year day. The Antarctic area is continuing to track close to the 1979-2000 average for a maximum area of about 15 Mm2 or 1 Mm2 less than 2007.

410. Kenneth Fritsch
Posted Aug 8, 2008 at 11:01 AM | Permalink

While not capable of critiquing the literary flow of these baby ice tales and as moved as all readers here must be by the renditions of jezz, I do find some elements of content that both conflict and agree with what I have come to expect from modern writings that deal with these climate related tales of survival.

In the episode at #360, we have the reference to “nature’s crucible” which I had anticipated as “nature’s crucible by man made unnaturally and unreasonably hot”. It rather breaks the flow but is something that the responsible writer must add.

Similarly, at #360 we have, “The survivors spread out to mourn his passing in advance for they have seen this pattern unfold too many times to cling to false hopes.” Which I am accustomed, more responsibly, even if less poetically, to be stated as something like: “The survivors, having no measure of this unprecedented pattern, are reduced to a chaotic and pitiful anticipation of his mourning.”

Then at #390 we see a glimpse of what could be in anticipation of the writings to come with the responsible, yet flowing, message of “Survival of the pod during this unprecedentedly grueling span of torment is not the only concern, for the unthinkable must now be thought, survival of the baby ice species may be at stake.”

The metaphor is not lost on me: baby ice is us and our future generations — and why would not it make me root for baby ices.

411. Luis Dias
Posted Aug 8, 2008 at 11:06 AM | Permalink

What’s with the references to revisions in the order of magnitude of kilometers? I thought the numbers were about millions of kilometers, which means that the revisions are about thousand kilometers, not kilometers?

Sorry bout the kilometer word abuse in here.

412. DeWitt Payne
Posted Aug 8, 2008 at 11:40 AM | Permalink

Luis,

The areas or extents are usually reported here in Mm2 or square megameters which is equal to one million square kilometers. JAXA lists the extent in km2. So a correction of 0.1 Mm2 is equal to 100,000 km2. If you go up far enough back on this thread you can see how many times and ways I messed this up before I got the units correctly named.

413. Luis Dias
Posted Aug 8, 2008 at 12:07 PM | Permalink

Payne,

Thanks. So when someone talks like this

As BarryW mentioned, the final numbers for yesterday’s extent area reduction revised the extent area upwards by about 8 km^2

he’s actually meaning 8 thousand km^2.

414. UK John
Posted Aug 8, 2008 at 12:42 PM | Permalink

As Artic ice area/extent seems to be inversely proportional to the amount it is visted, studied, mapped and measured.

Has there been any study done of the effect all this on site surveying, ice breaking, media news trips etc. etc. has on the summer ice.

It is one of the most fragile environments on Earth.

415. Aaron Wells
Posted Aug 8, 2008 at 12:43 PM | Permalink

Payne,

Thanks. So when someone talks like this

As BarryW mentioned, the final numbers for yesterday’s extent area reduction revised the extent area upwards by about 8 km^2

he’s actually meaning 8 thousand km^2.

That was a typo on my part. It should have read 8,000 km^2. It appears I wasn’t careful when I typed that. My apologies for the confusion it caused.

416. Aaron Wells
Posted Aug 8, 2008 at 12:44 PM | Permalink

That was a typo on my part. It should have read 8,000 km^2. It appears I wasn’t careful when I typed that. My apologies for the confusion it caused.

Looking back through the thread at my posts, it appears that I have made that typo more than once. I will try to be more careful in the future.

417. Matt
Posted Aug 8, 2008 at 1:18 PM | Permalink

Hi all,
I can’t believe I just had to explain to a coworker why/how I was laughing out loud while reading a blog about arctic sea ice extent. When all said and done there should be a retrospective “Baby Ice” novelet published!

418. Luis Dias
Posted Aug 8, 2008 at 3:10 PM | Permalink

That’s alright, Aaron Wells. I am not in good health shape today, and it takes little to confuse me :)

419. TAC
Posted Aug 8, 2008 at 9:05 PM | Permalink

Preliminary Unofficial Day 221 Race Report
2008 has a very slow day, and has been passed by 2005.
8 9 2002 6.801250 NA
8 9 2003 6.932813 -0.099218
8 8 2004 7.199844 -0.108750
8 9 2005 6.467344 -0.046562
8 9 2006 6.635000 -0.054063
8 9 2007 5.565313 -0.083750
8 8 2008 6.470781 -0.014844

420. Aaron Wells
Posted Aug 8, 2008 at 9:10 PM | Permalink

Preliminary Unofficial Day 221 Race Report
2008 has a very slow day, and has been passed by 2005.
8 9 2002 6.801250 NA
8 9 2003 6.932813 -0.099218
8 8 2004 7.199844 -0.108750
8 9 2005 6.467344 -0.046562
8 9 2006 6.635000 -0.054063
8 9 2007 5.565313 -0.083750
8 8 2008 6.470781 -0.014844

Truly amazing!

421. DeWitt Payne
Posted Aug 8, 2008 at 9:18 PM | Permalink

Projected extent up slightly to 5.34 Mm2 +/- 0.57 on 9/15. My prediction is that the race with 2005 will go right down to the wire. The smoothed extent loss rate is now back in the range of previous years. I’m not about to call the turn yet, though.

422. Aaron Wells
Posted Aug 8, 2008 at 9:22 PM | Permalink

I knew that something was up when I saw the NSIDC daily graph of ice extent. It had been on a steep downward slope, but the most recent graph has a definite leveling off.

NSIDC Arctic Sea Ice Extent Graph

423. DeWitt Payne
Posted Aug 8, 2008 at 9:31 PM | Permalink

JAXA is a two day moving average so it’s very likely that one of the days that was averaged showed an extent gain.

424. BarryW
Posted Aug 8, 2008 at 10:13 PM | Permalink

Whoa, that’s an amazing change from the previous day and there doesn’t appear to be an equivalent rate from any of the other years for another week. 2008 gained on everybody. Depending on which one (this one or the day before) is the outlier, this may mean 2008 melt rate is coming back to the average rate. I doubt if it could hold that rate but 2005 is back in play and maybe even some of the others. Can’t wait for the next installment of the Saga of the Baby Ice!

DeWitt

If I got the calculation right, 9/15 is julian 258? So we’re looking at another 37 days or so. Brute force I get about 5.33 for the minimum for 2008 based on the average melt per day for 2003-1007 through that date.

Just eyeballing the data it looks like 2007 is going to run comparable melt rates to the other years through September which I find interesting given how it is treated as a harbinger of doom.

425. Aaron Wells
Posted Aug 8, 2008 at 10:21 PM | Permalink

If I got the calculation right, 9/15 is julian 258?

I’ve got 9/15 being day 259 in my spreadsheet. I think you would be right in a non-leap-year year.

426. Daryl M
Posted Aug 8, 2008 at 10:40 PM | Permalink

Re: 416 It is one of the most fragile environments on Earth.

Is it really? The wind and ocean currents push the ice flows around all the time. Sometimes massive ridges are created by this process. Ice breaks. Ice freezes. And so on. Does it matter if an icebreaker does it or wind or currents?

I would argue that permafrost is much, much more fragile than ice.

427. DeWitt Payne
Posted Aug 9, 2008 at 12:46 AM | Permalink

Brute force is what I’m doing. I take the current extent and subtract the remaining extent using the 2002 to 2007 average on the same day. To estimate the date of minimum extent I use a different remaining extent calculated by averaging each year’s remaining extent using the date of minimum extent each year as day 0. So day zero has zero remaining extent. Then I take the day that’s closest to the current remaining extent and one day before and after and subtract the calculated remaining extent from each. The day that’s closest to zero is the projected date. If it drifts far enough off, I have to add a day on one end or the other. The plot for 2007 is particularly ugly. 2008 has actually been well behaved so far because it’s staying so close to the 2002 to 2007 average.

428. STAFFAN LINDSTROEM
Posted Aug 9, 2008 at 12:55 AM | Permalink

#426 BarryW …”harbinger of doom”…I don’t know…
date in 1993 Aug-Sept to dito 2007 what is the difference??
If it’s not at least 75% compression/compaction/stacking up
I’ll eat some … ice hat …
BTW the Devil is in the details #403, D. Patterson, the Boyd
et al paper had a list of vessels Numero UNO Swedish icebreaker I/B
“Oden”, UK John #416, has done much damage to Arctic summer ice
since the early 1980’s, I believe…As you all?educated people know,
Oden is the same old Norse Chief of the Gods …”Odin”…[Compare Zeus…]
Another boat was the US submarine “Hawkbill” NUMBERED 666 …Need I say
more?? Its sail/tower is erected in SE Utah almost in desert…You
get the teleconnection … LOL!
In googling this I came across an article from Swedish News Program
“Aktuellt” [SVT1]…from 2005. Amongst other things, it claimed
that the polar bears of Wrangel Island [Ostrov Wrangelja] were stuck
there due to no ice. Polar bears are known as excellent long distance
swimmers, this summer 2 polar bears were shot in Iceland in June…
Wrangel Island is some 120-130 kms from the Siberian mainland…
BUT according to UIUC CDSI this[no ice around Wrangel Isl.] also happened in 1990, 1993, 1996[cold
year in the Arctic], 1999[cool year globally] 2002 and then every year
until 2007 when it still Sept 12 was some low concentration ice near
the mainland coast…

429. jeez
Posted Aug 9, 2008 at 3:04 AM | Permalink

Whether delivered by good fortune, new leadership, or a fickle change of heart from nature, finally, we witness a much needed respite for the baby ice pod. This, the first day in weeks not a single member was lost, infused a palpable sense of hope throughout the pod.

Relieved that his first day of responsibility went well, yet well aware that it may have simply been beginners’ luck, the alpha squashes any relaxation on the part of the relieved baby ice, for the danger is not past.

He instructs them to resume his plan, to continue the tight formation of the pod, bobbing in unison to signal other distant pods…setting in motion a chain of events that has not occurred for more than a thousand generations.

430. Chris
Posted Aug 9, 2008 at 3:27 AM | Permalink

8 8 2008 6.470781 -0.014844

#341 “I wouldn’t be resigned to 2008 beating 2006 just yet….” (3 days ago)
#344 “…we ought to see an imminent drastic slowdown in ice melt…” (3 days ago)
#371 “…it again seems more likely that the current high melt rate is temporary, and once weather patterns change, if anything the melt rate should be slower there than in 2006…” (2 days ago)
#380 “…once conditions change I do suspect that melts will turn sharply lower…” (2 days ago)
#390 “…I’m therefore confident again that the melt rate will slow dramatically very soon…” (2 days ago)
#408 “…I await tomorrow’s figures with bated breath…” (yesterday)
:) :) :)

Just thought i’d point this out, not to say I told you so, but because people will be wondering why the figures suddenly changed, and I believe my analysis was a good one. (Of course one day does not a trend make so I can’t yet claim with certainty to be vindicated….)

431. ared
Posted Aug 9, 2008 at 3:50 AM | Permalink

Jeez, what exactly is the new Alpha male’s plan? Events not seen for more than a thousand generations… are we talking Ice Age here? While I’m sure most of us wish the baby ice long and fortuous lives, I’m not sure I would welcome their distant offspring crashing down on my house…

432. MrPete
Posted Aug 9, 2008 at 4:10 AM | Permalink

ared, baby ice Alpha males don’t need to explain their plans. That’s why they are Alpha males. :)

433. BarryW
Posted Aug 9, 2008 at 6:55 AM | Permalink

Chris

Of course one day does not a trend make…

The wild card is the baby ice. Will it act the way the way the experts predicted with a high melt or not? I believe they said that the worst melt would be at the end of the season because of the thin, weak ice. My plots of the melt rates appear to show a fairly consistent slope for 2003-2007 for the next month, the question is will 2008 follow the same pattern.

434. BarryW
Posted Aug 9, 2008 at 7:44 AM | Permalink

Steve

I was looking at the output of the code you posted for processing the sea ice here and I had a question about the julian dates. The dd column, julian day of the year, starts at zero rather than one. I didn’t know if there was a reason for this or is this a bug, since I haven’t worked with julian dates before.

Steve:
that should be 1. I fixed it in the script that I use here, but forgot to update the online version. It doesn’t affect any calcs, only the numbering.

435. Chris
Posted Aug 9, 2008 at 8:02 AM | Permalink

#435
To be honest, the baby ice issue looks to be over.
– The ice boundary on the Beaufort sea side of the Arctic Basin approached the 2007 minimum some time ago (n.b. likely due to the record far north Canadian heatwave in July), so any further melt would largely not be baby ice.
– On the European side of the Arctic Basin, the 2007 minimum was nothing very special compared to previous years, and so the heavier ice than normal around Svalbard this summer – http://arctic-council.org/article/2008/8/more_ice_than_expected – is no more likely to suddenly start melting quickly away than the heavy ice there in 2003 or 2000.
– Which leaves us with the Siberian seas. 2007 melt was absolutely spectacular in this “quadrant” of the Arctic. But the best analogy here would be with 1990/91. In 1990, the minimum extent in this area was significantly closer to the North Pole than the current extent – http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=09&fd=15&fy=1990&sm=08&sd=08&sy=2008 Which means that the ice at the current boundary was also baby ice in 1991. But if you look at what happened between 1990 and 1991, the ice grew back here. Moreover, MSU satellite data covering the North Polar region (#405) shows that summer 2008 so far has been colder than summer 1991 (+0.52C compared with +0.56C anomaly)
– As if more evidence was needed, instead of the extreme anomalously warm water being pushed in through the Bering Strait like happened in Jul/Aug 2007 (the one-off cause of the record melt and the reason we’re all here analysing 2008 now!) this year with the incipient PDO shift the waters close to Alaska are anomalously cold and we’ve even seen refreezing last week close to the north Alaskan coast. Not to mention that global temperatures have plummeted since the late July peak http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+002 and I wouldn’t be surprised if Arctic temperatures have been following suit (certainly that’s the impression I get anecdotally.)
– I’m sure 2007 has had a knock-on effect on 2008, but I would say it leaves 2008 currently with much less ice than it should have for the current temperature, which means that the ice may well be poised to freeze back even more quickly than last year. Certainly I think this could start happening surprisingly soon in the Arctic Basin/Beaufort Sea ice boundary (seeing as this is so close to the Pole where insolation is already geting very low)

436. Posted Aug 9, 2008 at 8:10 AM | Permalink

Re #436
I don’t know why they’re calling it the Julian date since the Julian date is a continuous count of days and fractions since noon Zulu Time on January 1, 4713 BCE. It’s just the ‘day of the year’ and conventionally starts on day 001 (Jan 1st).

437. kim
Posted Aug 9, 2008 at 8:15 AM | Permalink

Chris is teleconnected to the Baby Ice’s Alpha Male.
================================

438. Chris
Posted Aug 9, 2008 at 8:22 AM | Permalink

Yesterday’s ice extent reduction revised down to 625km!!!!!! (Yes no missing zeros!!)

08,07,2008,6485625
08,08,2008,6485000

439. BarryW
Posted Aug 9, 2008 at 8:23 AM | Permalink

Chris

So it appears that the majority of the baby ice that was at risk is already gone. The average melt rate graph shows a sharp trend downward from this point forward for the next 30 days which would seem to correlate with the insolation drop you mentioned. Right now seems to be some sort of phase change point based on the change is slope for the melt rates (some critical value for insolation or length of daylight?).

440. Chris
Posted Aug 9, 2008 at 8:28 AM | Permalink

625 km/2 (Doh! No missing zeros but managed to miss the /2)

441. John Lang
Posted Aug 9, 2008 at 9:22 AM | Permalink

Obviously, they overstated the melt rate in the last 3 days (the 145,000 km2 was clearly out of place) and now they have to make up for it.

The way the NSIDC operates, one never knows what they are planning to do with the data next.

442. Chris
Posted Aug 9, 2008 at 9:30 AM | Permalink

#443 Are you sure?

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=04&fy=2008&sm=08&sd=07&sy=2008

443. Chris
Posted Aug 9, 2008 at 9:43 AM | Permalink

Though technically the “melt rate” (as opposed to ice extent/area reduction) was indeed probably not as much as it appeared. This is because the strong low in the Siberian seas, as well as undoubtedly causing significant melt, also clearly compacted some of the ice (see how the tongue of ice in the Siberian sea turns to dark purple in #444 link)

444. DeWitt Payne
Posted Aug 9, 2008 at 10:23 AM | Permalink

CT Ice Area 8/8/2008
Area difference anomaly
Arctic
4.323 -0.052 -1.655
Antarctic
13.727 -0.022 -0.175

445. Chris
Posted Aug 9, 2008 at 10:41 AM | Permalink

#431 and #439
The alpha (and his confidantes) know his work may be completed almost as soon as it is begun. Now could it be that the key to the “chain of events that has not occurred for more than a thousand generations”, albeit masked by human efforts, lies in the southern seas and skies, where warm seas and trade winds, locked in an epic struggle, wait yet to see which way the balance will tip, watched over by a quiet yet inscrutable sun………………………………………………………..

446. Aaron Wells
Posted Aug 9, 2008 at 12:18 PM | Permalink

Here are my graphs for yesterday’s ice extent data. I’m inclined to agree with those who say that this is a make-up for overstating the reduction the past couple of days.

Daily Arctic Sea Ice Extent Reduction Day 221

Arctic Sea Ice Extent Day 221

2008 Arctic Ice Extent Differences From Previous Years Day 221

447. BarryW
Posted Aug 9, 2008 at 1:24 PM | Permalink

We’re starting into the turn from the back stretch. The baby ice is in the back of the pack, but moving to the outside. Is baby ice about to make it’s move?

448. BarryW
Posted Aug 9, 2008 at 1:44 PM | Permalink

Chris

I know I’ve been playing fast and loose with the term “melt” when the reduction could just as easily been due to compaction.

I’d give the providers the benefit of the doubt as far as day to day extent numbers go, I think there is too many variables that could enter into any one answer.

449. Steve McIntyre
Posted Aug 9, 2008 at 2:05 PM | Permalink

#451. If you look at #351, it looks like “area” flattens out before “extent” suggesting that compaction is very relevant to August results.

450. TAC
Posted Aug 9, 2008 at 9:03 PM | Permalink

Preliminary Unofficial Day 222 Race Report
2008 has an ordinary day, remaining a bit ahead of 2005.

8 10 2002 6.747969 -0.053281
8 10 2003 6.909688 -0.023125
8 9 2004 7.111875 -0.087969
8 10 2005 6.410000 -0.057344
8 10 2006 6.589219 -0.045781
8 10 2007 5.527813 -0.037500
8 9 2008 6.420781 -0.064219

451. WhiteBeard
Posted Aug 9, 2008 at 9:07 PM | Permalink

#437 Chris,

I think you may be off on a few points. The SST graph you posted a few days ago with your assertion that a warm water inflow through the Bearing Straits was the prime determinant for the spatial pattern of last years melt is a result of atmospheric transfer of heat to that area, not heat carried into the Arctic Basin from the Bearing Sea. What you’re seeing is the increased anomaly resulting from the adsorption of energy in areas that were open water but had been ice covered, or had become ice free at a later date, during the base period (1971 to 2000).

I just spent a good bit of time looking, but didn’t find any source agreeing with your current from the Baring Sea statement. I do recall something about a regime change where Bering Sea water was entering the Chuckchi Sea, but my memory is that this was for an earlier period than last year, and in measurable but not highly significant amounts. If you have a source that records data on this flow in 2007, particularly if it points to extraordinary conditions, could you point me to it?

What seems to have recently occurred is similar to what happened in late June and early July of 2007 in roughly the same location. A lot of warm air flowing off eastern Siberia produced a rapid growth in ice free ocean. That produces melt, as well as compacts the ice.

There has not been a refreezing along the Alaska cost. A tongue of the polar pack running southeast from about 75 north and 165 west to the Alaskan coast at Barrow has been a feature of this year’s season. It grounded for a time in the Barrow area in late July.

Interesting that you provide a link to a side by side comparison in support of the idea that 1990 is the best prior for the East Asian sector of the Arctic Seas, but chose to compare the current state with September 15th of 1990. Since this area had the greatest amount of open water at the time of minimum coverage in 2007, and that lead to much of its area being skinned this past winter season by young ice, why would you suppose that it’s home free. In a year’s time the ice does move, but the basic ratio between young, thin and older, thicker ice doesn’t seem to have changed radically in that local. Do a comparison between now and the end of the melt season, say September 15, and the further reduction in exactly the area you feel will survive is vary large.

Nice site you linked to in support of your statement that temperatures have dropped recently. It appears the global average has cooled quite a bit in the last ten or so days, but what leads you to suppose that this cooling rate is necessarily applicable to the Arctic. You might note, at the closest elevation to the surface (1 km) that they provide a reading, for August 7th (the most recently reported date when I accessed) is about half the spread between last years temperature and the “20 year record high”. Since the difference between the three (2007, 2008, 20 yr record – in descending order of temperature) is less that the amount all are above the “20 year average” I’d say that didn’t bode well for high ice coverage at season’s end. Again, that’s if there is much of a link between the global average and Arctic conditions. The most recent trend is down, though.

For quite some time, the SST off Alaska’s costs below the Bearing Straight has been cool to cold. From north of that passage, and on around to the Canadian Arctic Islands the temperature has been high and going up in coastal waters over the last several months. Alaska’s summer has been much colder than those of late, but how do lower land and southern coastal waters temps factor into what’s happening to the north of there, where it’s been warmer than normal.

I’d suspect there are 3 pertinent considerations I can’t recall seeing mention or stressed here.

Off Eastern and Central Siberia, where ice loss has been dramatic of late, June and July’s SST’s have been cool, as the water in those areas lacked much direct solar gain until very recently. They haven’t had anywhere near as long to accumulate heat for transfer later in the season as they did in 2007, and what they have recently gained has to be at a lower rate, as the sun angle is lower later in the year.

Against that and if I’m not wildly off in looking at the graphic images, the fraction of surface with actual coverage is much lower than at this date last year. There is more low albedo open water within the perimeter of the area covered. I recall a mention of the spread between extent and area values, enough chapters back in the saga of the babies to keep me from re-reading to get the specifics. It doesn’t look as highly packed and the area west of the Canadian Arctic Islands has been “looser” for a long time. The area to the east of the New Siberian Islands, the ones in the recently opened area, seems to have low concentration, and its relatively far south.

Finally, it all depends on where the weather lurches over the next 5 weeks.

452. TAC
Posted Aug 9, 2008 at 9:09 PM | Permalink

Oops! Make that “behind 2005″.

2008 remains ahead of 2006 and actually widened the gap a bit.

453. DeWitt Payne
Posted Aug 9, 2008 at 9:29 PM | Permalink

Projected minimum extent still 5.3 +/- 0.5 Mm2 on 9/14.

If you want to see high definition footage of a nuclear sub breaking through the ice in the Arctic Sea about 200 miles north of the Alaska coast (82.7 latitude) rent Stargate: Continuum. Three members of the cast and of course a film crew went to the APLIS station in 2007 to shoot scenes for the film.

454. AndyW
Posted Aug 9, 2008 at 10:31 PM | Permalink

I’m tending to go for a correction as per John Lang’s post, as 145 000 was out of the ordinary so is 625. Now it’s back to a slightly above normal 64 000 km2 before correction. I know it can very but you can’t have just compactive effects for just one day surely?

I think Chris is still on a sticky wicket here and he proclaimed himself the victor far to early :p

Regards

Andy

455. Chris
Posted Aug 10, 2008 at 12:46 AM | Permalink

#437 Thanks for a great post!

I agree that I was over-simplifying re: the warmer seas in the Arctic last summer. What I meant was that the anomalously warm winds flowing northwards, or “atmospheric transfer of heat to that area” as you refer to it, speeded the melt of the ice via warming of the seas. So yes it wasn’t a current as such, although the net movements of the surface water would have been northwards, and its temperature was high above average.

Again, I think you’re a little harsh when it comes to ice on the Alaskan coast. Surely my eyes are not deceiving me when I see that the tongue of ice extends all the way to the coast now where it didn’t on 29th July http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=07&fd=29&fy=2008&sm=08&sd=09&sy=2008 Ok I’m happy to re-word from re-freezing to re-icing but I don’t think it negates my point.

Re: 1990/91 I was making a very subtle point about ice at the margin. Sure there’s currently areas much closer to the pole that were open water in mid-Sep 2007. But what matters in the short term is ice at the margin and there’s no reason this should be thinner now than in 1991 if you think about it.

Aha you’ve spotted the issues with MSU data concerning surface vs higher level temps, and 20-year averages! There’s some complicated issues here, and it would be off-topic to go into them here (I raised them in another thread where I was essentially saying doesn’t the near-surface satellite record suggest AGW?) ….. But in a nutshell I now believe the 14,000 ft data is a better guide, you can take this or leave it….

I think you may have missed my point somewhat re: cold coastal water around Alaska. As you will see from the latest sea surface temperature anomaly map http://weather.unisys.com/surface/sst_anom.html , the cold anomalies wrap right around the NW coast, and the East Siberian Sea appears to be colder than average as well.

“Finally, it all depends on where the weather lurches over the next 5 weeks.” Here I couldn’t agree more, as I’ve been painstakingly trying to explain to people recently why meteorology is important to understanding Arctic ice melt, and if I’ve got elements of the meteorology wrong with the limited time and charts I’ve had available, I don’t think this detracts from the argument that weather patterns have been the main varying factor in the short term (while the baby ice has remained baby ice and the data collecting agencies have continued to do their job)

#456 I’m not interested in being a victor, I just want to understand how global climate works, including in particular the Arctic where last summer’s melt was deeply concerning. But in terms of declaring victory, absolutely. I was the countering the idea that melts of 100,000, 140,000 spelt a tipping point for baby ice where it was suddenly headed for meltdown (pardon the pun!) for the rest of the month, and it’s looking like I’ve been proved right on this.

456. Chris
Posted Aug 10, 2008 at 12:49 AM | Permalink

“#437 Thanks for a great post!”

Oops I meant #453!!! I’m not that vain……….. :)

457. Kimberley Cornish
Posted Aug 10, 2008 at 2:21 AM | Permalink

One would think that we are approaching the time when pubertal hormones will start to act on the baby ice, now no longer really accurately described as “baby”. Much to-ing and fro-ing will ensue with the alpha male’s dominance repeatedly challenged. Could Jeez let us know the names to the alpha male and his intended? I recall Bambi and Faelene(?) from the days of my youth and the epiphany of Bambi’s final religious realization. Something like that, with Johnny Depp as alpha and Keira Knightley as the prettiest ice-cube in a background of the Northern Lights would be terrific.

458. Syl
Posted Aug 10, 2008 at 5:11 AM | Permalink

I don’t know if this is appropriate, but I made an image of Baby Ice and dedicated it to jeez. I’ll try to post a thumbnail here. The original and also a larger version can be found at my site http://www.cricket-studio.com.

Steve: Perfect for my grand-daughter. Does she sing “Ice, Ice Baby” ?

459. jeez
Posted Aug 10, 2008 at 5:28 AM | Permalink

Notoriously independent and competitive, differing baby ice pods are not generally known for either communication or cooperation of any kind during the summer phase. Competition and hostility, even outright battles are the norm as the pods compete for dominance. The seas are strewn with the shards left over from these never ending clashes.

Under extreme conditions, conditions so dire they threaten the very existence of all, this behavior can not only change, but change so dramatically that the all pods will suddenly act in concert under the guidance of a single alpha. This alpha, the new leader of our familiar pod, has recognized instinctively that this time has come.

The last time this bobbing bulletin was broadcast across the sea was during the unspeakable bright time, the Melting Water Period, more than a thousand generations past. The horror of that time is buried as an ancestral memory in all individuals of each of the pods as well as the steps necessary to survive again.

460. Chris
Posted Aug 10, 2008 at 6:12 AM | Permalink

Today’s Observer (/Guardian online) has picked up on the events of earlier this week.

http://www.guardian.co.uk/environment/2008/aug/10/climatechange.arctic

(n.b. the Guardian is one of the most influential newspapers in the UK)

They describe what happened as follows:

“Satellite images show that ice caps started to disintegrate dramatically several days ago as storms over Alaska’s Beaufort Sea began sucking streams of warm air into the Arctic.”

Then there is the inevitable AGW spin: “As a result, scientists say that the disappearance of sea ice at the North Pole could exceed last year’s record loss. More than a million square kilometres melted over the summer of 2007 as global warming tightened its grip on the Arctic. But such destruction could now be matched, or even topped, this year. ‘It is a neck-and-neck race between 2007 and this year over the issue of ice loss,’ said Mark Serreze, of the US National Snow and Ice Data Centre…”

Later on in the article, a confident verdict is given that the baby ice has already failed this summer:
“‘It does not really matter whether 2007 or 2008 is the worst year on record for Arctic ice,’ Maslowski said. ‘The crucial point is that ice is clearly not building up enough over winter to restore cover…”

It seems we could be at quite a critical moment in history. Was the 2007 record Arctic melt a freak event associated with a peak in global temperatures in the years leading up to it, and unlikely to be repeated in the next few years now that the globe has been cooling significantly? Or did it represent a tipping point towards an impending step change further upwards in global temperatures, after a deceptive brief respite caused by the 2007/8 La Nina?

I believe that the “dramatic slowdown” I correctly predicted in ice extent reduction (i.e. approx 30,000 km/2 per day on average for last 2 days, compared with approx 110,000-120,000 km/2 per day for the previous 3, suggests that today’s article has already been made somewhat out of date by events. But no one can be sure what will happen, and the only thing I can predict is that I will find it impossible to keep myself away from watching this tortuous saga evolve.

(N.b. the following opinion piece is in the newspaper under the main feature http://www.guardian.co.uk/environment/2008/aug/10/climatechange.scienceofclimatechange – “…my trip with Denmark’s minister of climate and energy, Connie Hedegaard, to see the effects of climate change on Greenland’s ice sheet leaves me with a very strong opinion: our kids are going to be so angry with us one day…”)

Steve: I urge CA readers, especially those who’ve been following the travails of Baby Ice, to read this account of “unprecedented” ice loss, with quotes from a couple of eminent sea ice specialists (Sarrukh was a rock star at last year’s AGU, sort of like the hurricane people in 2005-6.)

461. Chris
Posted Aug 10, 2008 at 8:52 AM | Permalink

(See #462 and link to today’s Observer article)

“…the Beaufort Sea storms triggered steep ice losses…” [Mark Serreze, of the US National Snow and Ice Data Centre in Boulder, Colorado]

He’s the ice expert, but has he got the meteorology right?

Here’s the pressure charts for the last 7 days:

http://www.opc.ncep.noaa.gov/Loops/UA_Entire/UA_Entire_07_Day.shtml

(best to slow the animation speed, and keep clicking on Stop/Start to get the individual frames)

First off, don’t be distracted by the low on 3rd Aug in the Bering Strait: there is nothing to suggest that this brought significant amounts of warm air anywhere.

Now watch the steady stream of southerly winds brought up over the Siberian coasts from 4th-6th Aug by a large and complex low pressure system to the west, with the powerful warm front making significant inroads northwards into the Arctic on 6th (the day of the 140,000km/2 sea ice reduction, which if you look at http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=05&fy=2008&sm=08&sd=06&sy=2008 happened without a shadow of a doubt in the Siberian seas, not the Beaufort Sea – as implied though not stated by Serreze).

Meanwhile, note that in the Beaufort Sea, at no point were there a significant southerly airstream – indeed a ridge of high pressure built there from 5th Aug. (Yet recall Serreze’s confident assertion quoted at the top).

Yet we are told the following: “..Satellite images show that ice caps started to disintegrate dramatically several days ago as storms over Alaska’s Beaufort Sea began sucking streams of warm air into the Arctic…As a result, scientists say that the disappearance of sea ice at the North Pole could exceed last year’s record loss.”

Disintegrating ice caps? Scientists predicting things as a result of something that didn’t happen? I think there’s something wrong here.

462. BarryW
Posted Aug 10, 2008 at 9:23 AM | Permalink

There’s a lot to read today, but I thought I would make a few observations. In looking at the extent differences, 2008 vs 2007 have been following the same track, keeping roughly a constant separation since about day 190 and 2007’s extent loss over the next week looks about average after which it starts increaing. 2008’s extent is running just below the average for 2003-2007, but, of course the average is pulled down by 2007. It looks like the closest year to the average extent is 2006. Over the next week the average extent loss is on the order of .05.

463. BarryW
Posted Aug 10, 2008 at 9:51 AM | Permalink

Chris

Wishful thinking on their part? Could the reporter have gotten his seas confused? It looks like a few days of high loss sent them into a frenzy thinking that they’re prognostications were being vindicated. With the low extent loss (“correction”?) right afterward they didn’t even get the article into print before the facts started catching up with them.

464. Chris
Posted Aug 10, 2008 at 10:02 AM | Permalink

You’re gonna love this…….

Forgive me if I’ve got this wrong in my haste as it’s the first time i’ve reported it:

CT Ice Area anomaly has gone from -1.655 yesterday to -1.583, that’s a reduction in anomaly of 0.072!

465. tty
Posted Aug 10, 2008 at 10:04 AM | Permalink

Re 437

According to the Canadian Ice Service there is essentially no young ice left in the Beaufort Sea, though oddly the very persistent ice off Point Barrow is first-year:

466. Chris
Posted Aug 10, 2008 at 10:40 AM | Permalink

#466 – Took me a while to get my head around the CT format. Can I now add that the ice area itself went UP from 4.323 to 4.336 yesterday!!! Plus looks like Antarctica had sharp rise too…

#465 – I don’t think you can realistically claim that both CT and JAXA have made errors, I think you’re going to have to accept there’s been at least some meteorological influence :)

467. DeWitt Payne
Posted Aug 10, 2008 at 10:43 AM | Permalink

CT shows Arctic area increase.

area difference anomaly
Arctic
4.336 0.013 -1.583
Antarctic
13.760 0.033 -0.182

Comparing the last few days, it looks like CT may be one day behind, and is definitely a lot noisier than JAXA. Given the difference in resolution reported above by Phil, the noise is not surprising. It looks to me as if the data are the data and there is no need to invoke ‘corrections’ to explain unusually large day to day differences.

difference from previous day Mm2
Date JAXA CT
8/1 -0.10 -0.05
8/2 -0.10 -0.005
8/3 -0.09 -0.04
8/4 -0.07 -0.17
8/5 -0.12 -0.32
8/6 -0.14 -0.10
8/7 -0.09 -0.16
8/8 0.00 -0.05
8/9 -0.07 0.01

468. Daryl M
Posted Aug 10, 2008 at 11:00 AM | Permalink

I came across a link to an article on “the daily green” about “Students on Ice”. This site is a veritable treasure trove of hyperbole and propaganda relating to polar ice and other global warming issues.

In the aforementioned article, we hear that “Auyuittuq National Park was closed earlier this week due to mass flooding as glaciers melt at exponential speed“. Here is a link: http://www.thedailygreen.com/environmental-news/community-news/students-arctic-88080901.

In another article we hear that “scientists from NASA reported yesterday that the extent of Arctic sea ice shrank to its lowest level ever recorded” and of “Unprecedented Melting in Antarctica“. Of course, this leads to the predictable fear mongering about global flooding. Here is a link: http://www.thedailygreen.com/environmental-news/latest/7016.

This is OT, but there is another article containing an expose on the “deniers” referenced in Senator Inhofe’s report “Over 400 Prominent Scientists Disputed Man-Made Global Warming Claims in 2007″.

469. David Smith
Posted Aug 10, 2008 at 11:01 AM | Permalink

Updated insolation plot ( link ) . The red dot is 10 August.

470. Chris
Posted Aug 10, 2008 at 11:21 AM | Permalink

#465 Barry – Sorry zeroed in on the word “correction” but didn’t deal with the rest!

All sounds possible to me, and it certainly seems the facts have been catching up with both the NSIDC and the Observer. As a meteorologist (well…when I graduate….) I’m just flummoxed by the reference to Beaufort Sea storms….. But then at the same time I find it amazing an expert could get it so wrong so I don’t want to stick my neck out too far……

I’d hate it if they turn out to be right for the wrong reasons i.e. if weather patterns turn anomalously warm/windy again. So I’m going to await tomorrow’s figures with bated breath again……

471. DeWitt Payne
Posted Aug 10, 2008 at 11:23 AM | Permalink

David Smith,

Considering that from 2002 to 2007 the minimum extent date ranged from 9/9 to 9/24, 200 W/m2 seems a little high. Of course extent probably ranges somewhat south of 80 N.

472. Chris
Posted Aug 10, 2008 at 11:32 AM | Permalink

Here’s another great link I just found – Arctic ocean temperature watchers/guessers eat your heart out! (I wish I’d found it earlier…..)

(There’s other goodies as well at http://www.weatheroffice.gc.ca/analysis/ )
Just to cherry-pick one figure, the -4C not a million miles from the North Alaskan coast looks promising from the point of view of re-freezing :)

473. Aaron Wells
Posted Aug 10, 2008 at 11:48 AM | Permalink

Here are my graphs for yesterday’s ice extent data.

Daily Arctic Sea Ice Extent Reduction Day 222

Arctic Sea Ice Extent Day 222

2008 Arctic Ice Extent Differences From Previous Years Day 222

474. David Smith
Posted Aug 10, 2008 at 11:57 AM | Permalink

Re #473 Agreed, DeWitt, but the use of the term “near-zero” is to reflect that whatever melting may be underway is quite slow at 200W/m2 and may be due to the presence of warmed open water or some other factor besides sunlight. The use of the line is to illustrate that insolation doesn’t have to go all the way to zero before melting stops.

475. Hoi Polloi
Posted Aug 10, 2008 at 12:18 PM | Permalink

From the Graudian:

Meltdown in the Arctic is speeding up

Ice at the North Pole melted at an unprecedented rate last week, with leading scientists warning that the Arctic could be ice-free in summer by 2013.

Satellite images show that ice caps started to disintegrate dramatically several days ago as storms over Alaska’s Beaufort Sea began sucking streams of warm air into the Arctic.

As a result, scientists say that the disappearance of sea ice at the North Pole could exceed last year’s record loss. More than a million square kilometres melted over the summer of 2007 as global warming tightened its grip on the Arctic. But such destruction could now be matched, or even topped, this year.

http://www.guardian.co.uk/environment/2008/aug/10/climatechange.arctic

476. Chris
Posted Aug 10, 2008 at 12:32 PM | Permalink

Re: #477

There is a discussion/deconstruction :) of this article (and the comments by the NSIDC expert) at #462 and #463

477. Posted Aug 10, 2008 at 1:17 PM | Permalink

Re #473

Considering that from 2002 to 2007 the minimum extent date ranged from 9/9 to 9/24, 200 W/m2 seems a little high. Of course extent probably ranges somewhat south of 80 N.

Here’s some actual measurements at ~83ºN:buoy data

The CT data is reported about 12hrs later than JAXA and seems to refer to the previous day (the map is so dated).

478. BarryW
Posted Aug 10, 2008 at 1:37 PM | Permalink

#471

I shouldn’t have used the quotes around correction since that implied a screw-up or worse on their part. Since I haven’t looked at the instrumentation and algorithms they’re using I don’t know what the odds are that they could get an anomalous answer.

We’ll have to wait to see what the next few days brings.

#470

I don’t think our host wants to see links to religious sites like the one you referenced (grin)

479. David Smith
Posted Aug 10, 2008 at 3:06 PM | Permalink

Here’s a plot with warts. I offer it despite the warts because I think illustrates that both ice coverage and the time of the year of ice coverage are important. Also, I’m interested in readers’ ideas on ways to improve this.

The presence of ice at summer solstice is more important to reflecting sunlight than is the presence of ice in the low sun of, say, September.

To develop an insolation-weighted ice coverage I multiplied daily TOA insolation (I chose 80N as representative) by daily ice extent (I don’t have ice area data) and summed these daily values into a running sum over the course of the melt seasons. The higher the number, the greater the amount of sunlight which ice reflected so far in that season (assuming that all other factors are equal).

The plot is here .

What it indicates is that, while 2008 ice has now lost some ground to earlier seasons, it had higher ice coverage during the important strong-sunlight times of early and mid summer.

How can this be improved? Use of area data seems obvious but what else needs to be modified in the approach?

480. Larry T
Posted Aug 10, 2008 at 3:35 PM | Permalink

Re. 479 — I noticed that the buoy has moved from 88.5 degrees to 84 degrees. Doesn’t this compromise the data especially the temperature which has moved from -25 range to the -5 range.

481. Posted Aug 10, 2008 at 3:35 PM | Permalink

Re #472

I’m just flummoxed by the reference to Beaufort Sea storms….. But then at the same time I find it amazing an expert could get it so wrong so I don’t want to stick my neck out too far…

It could be that the interview was a few days ago, see below

FECN14 CWIS 011800
THIRTY DAY ICE FORECAST FOR THE WESTERN AND CENTRAL ARCTIC FOR AUGUST
ISSUED BY ENVIRONMENT CANADA ON 01 AUGUST 2008.
THE NEXT 30 DAY FORECAST WILL BE ISSUED ON 15 AUGUST 2008.

Mean air temperatures during the last 2 weeks of July were normal
over most regions except below normal near the Mackenzie Delta. Breakup
in the central Arctic is near normal but the situation in the Western
Arctic bears little resemblance with past breakup patterns because the
southern Beaufort Sea is so open. During the last 2 weeks of July, the
fast ice fractured in the Coronation Gulf and Queen Maud Gulf as
predicted but Larsen Sound and the Peel Sound fractured 7 to 10 days
earlier than forecast. Although M’Clintock Channel is still mostly
consolidated, Parry Channel is fractured which represents a pattern
roughly 10 days earlier than normal. The ice along the shore near Point
Barrow melted sufficiently to allow the open drift or less route as well
as the open water route the to develop in that area.

Forecast ice conditions for August 01st to August 15th.

A deep low pressure system over the Beaufort Sea will quickly
weaken and move towards the pole. A series of weak disturbances will
then move across the western and central Arctic until a high pressure
area builds north of Point Barrow during the second week of August.

Moderate to strong southerly winds will abate to light to moderate
westerly winds until the high pressure builds; then, moderate winds will
prevail from the north almost everywhere. Mean temperatures will remain
above normal over the central Arctic, however, normal to below normal
temperatures are expected west of Banks Island. During the first half of
August, the ice will clear from the Coronation Gulf area and melt at a
moderate pace in Peel Sound, Larsen Sound and the Queen Maud Gulf. This
will leave only very open to open drift mostly first-year ice
concentrations with small areas of close packed ice in the central
Arctic portion of the Northwest Passage by the end of the period. The
Northwest Passage across Viscount Melville Sound will also be subjected
to moderate melt and this will promote open drift to close pack ice
concentrations to develop during the period. The consolidated ice in
M’Clintock Channel will fracture and ice will melt leaving close packed
concentrations in the region. The Amundsen Gulf will clear of all
remaining ice save a few strips of old ice trickling southward from the
Prince of Wales Strait. The Beaufort Sea will continue to be wide open
with very open drift multi-year ice concentrations remaining beyond 100
miles of the coast. Open drift to close packed multi-year ice will
prevail in the central portion of the Beaufort Sea south of 79°N. The
Point Barrow region will be challenging with periods of onshore winds
bringing open drift to close pack first-year and multi-year ice
concentrations closer to the coast during part of the period as slow
melt is forecast in that region.

482. Posted Aug 10, 2008 at 3:55 PM | Permalink

Re #467

According to the Canadian Ice Service there is essentially no young ice left in the Beaufort Sea, though oddly the very persistent ice off Point Barrow is first-year:

The lack of ‘young ice’ was a result of the break-up of the multi-year ice off Bank’s island last winter which spread fragmented multi-year ice throughout the Beaufort Sea and set it up for the exceptional melt this year.

483. Posted Aug 10, 2008 at 4:05 PM | Permalink

Re #482

Re. 479 — I noticed that the buoy has moved from 88.5 degrees to 84 degrees. Doesn’t this compromise the data especially the temperature which has moved from -25 range to the -5 range.

The data is what it is, why would it be compromised?

484. Larry T
Posted Aug 10, 2008 at 4:20 PM | Permalink

Phil, my scientific experience is with radio telescopes and if we move the darn things it is considered a different station location. Even 2 of them in the same physical location are considered different station locations. Maybe I should not say the data is compromised but maybe drawing conclusions from the data is, if you do not take in the dynamics of the moving location. I have similar problems with land based weather stations that are moved and the data from the multiple locations are tried to be combined into a single continuous vector. My experience shows that the data should be analyzed as seperate vectors that you may be able to fit to a curve, throw out as outliers, or considered separately.

I was in a previous life an applied mathematician, before I got into scientific programming and then on the data base / data integrity

485. DeWitt Payne
Posted Aug 10, 2008 at 10:27 PM | Permalink

Another day another ice extent. I’ll let someone else post the full details, but the projected minimum didn’t change significantly, still 5.3 Mm2 but now closer to 9/15 than 9/14, and the extent rate is still tracking the 2002 to 2007 average. For 2008 to catch 2007 extent loss would have to average nearly 20,000 km2/day higher than the average for the rest of the loss season and have a much later minimum date than currently expected. Right now, the smoothed extent rate is tracking 2007 fairly closely (as well as several other years) so it seems incredibly unlikely that 2008 will come close to 2007 much less pass it. The race is still with 2005 and much less likely, 2002.

486. Chris
Posted Aug 10, 2008 at 11:18 PM | Permalink

#483

The ice forecast is really interesting – have you got the link?

But all the evidence suggests the interview was in the last couple of days: note the past tense in “triggered” (‘But the Beaufort Sea storms triggered steep ice losses and it now looks as if it will be a very close call indeed whether 2007 or 2008 is the worst year on record for ice cover over the Arctic…)

At the end of July, Serreze was saying “The North Pole is likely safe for at least this year.”
(http://www.reuters.com/article/latestCrisis/idUSL0169173) Previously he was behind the story that the Pole could become ice free this summer http://abcnews.go.com/Technology/Story?id=4728737&page=1

I’ve not got it in for him – the media are always desperate for predictions and he/the NSIDC will have done the best they can at each stage (bearing mind that if melt was more than they predicted, they would likely get blamed and the word “unprecedented” would be flying around even more). It’s just that it seems very likely to me that the recent peak in ice extent/area reduction was not caused by storms in the Beaufort Sea, and the Observer article blew things out of proportion.

487. Chris
Posted Aug 10, 2008 at 11:24 PM | Permalink

#483 continued

Just so we’re clear, the quote in my last post “…’But the Beaufort Sea storms triggered steep ice losses…'” was from Serreze himself as quoted in the article.

488. Chris
Posted Aug 10, 2008 at 11:38 PM | Permalink

Re: latest extent reduction (approx 82,000 km/2 I make it) – seems to confirm again that increase in reductions a few days ago didn’t spell imminent disaster for the baby ice. But still quite a large reduction, and hoping it goes down in the next few days….. I notice the ice in the Siberian seas has continued to thin/melt visibly although there is little sign of further melt elsewhere http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=09&fy=2008&sm=08&sd=10&sy=2008

489. AndyW
Posted Aug 11, 2008 at 12:10 AM | Permalink

Thanks for that Guardian piece Chris, technically they are correct, the first 10 days of August have seen a very large amount of melting, however it is rather like waiting for something to happen and then pouncing on it as something to be amazed at.

I’m still happy with how it’s tracking in August also to indicate infanticide is happening. Finally, Aarons graph once again arouses my suspicions about the 145 000/625 km^2 days.

490. Chris
Posted Aug 11, 2008 at 12:31 AM | Permalink

#491: It does feel like that doesn’t it – the first couple of days of unusually high extent reductions for the time of year and they pounce!

Re: your suspicions note #468 above – are you seriously suggesting that both JAXA and CT got it wrong?

Re: “infanticide” – I’m certainly worried by continuing heatwaves in Siberia, and a couple of new “holes” that appeared in the last day in the satellite pics I linked to. Hard to predict the effects of the warm winds, and could be we’re not out of the woods just yet…………

Just to clarify yet again, I never said the baby ice didn’t make large melts possible. What I said was essentially:
warm winds + baby ice in the Siberian seas specifically = problem!

And of course I correctly predicted a dramatic slowdown. But I also said whether it continued depended on weather patterns. And the weather patterns at the moment aren’t looking good for baby ice (though not as bad as last week???)

491. jeez
Posted Aug 11, 2008 at 1:07 AM | Permalink

http://ice-glaces.ec.gc.ca/prods/FECN14G/20080801000000_FECN14G_0003890771.pdf

492. TAC
Posted Aug 11, 2008 at 1:26 AM | Permalink

Preliminary Unofficial Day 223 Race Report
2008 is now ahead of both 2005 and 2006
8 11 2002 6.681875 -0.066094
8 11 2003 6.887031 -0.022657
8 10 2004 7.057813 -0.054062
8 11 2005 6.372969 -0.037031
8 11 2006 6.536250 -0.052969
8 11 2007 5.468594 -0.059219
8 10 2008 6.335938 -0.081718

493. AndyW
Posted Aug 11, 2008 at 3:49 AM | Permalink

#492 >Re: your suspicions note #468 above – are you seriously suggesting that both JAXA and CT got it wrong?

I can’t see how anything can explain it going from around 10^5 down to 10^3 and then back up to 10^5 or so in 3 days. I cannot believe the main driving forces up there can do such a rapid swing, therefore a lot of the fluctuation on Aaron’s graphs must be due to measurement and interpretation errors and for that day there was, for whatever reason, a magnification of this both ways in succession.

As for dramatic slow down, I see no example of this at all, 2008 seems to be still steaming on into August compared to other years. Even 2007 for this period.

494. Mike Bryant
Posted Aug 11, 2008 at 4:29 AM | Permalink

2008 is closer to 2004 than it is to 2007.

495. Stan Palmer
Posted Aug 11, 2008 at 6:13 AM | Permalink

Unprecedented melting — any truth to this??

496. Chris
Posted Aug 11, 2008 at 7:00 AM | Permalink

#497: *Some* truth re: 4-7 August (see below), especially in terms of ice area. I don’t have figures for ice area to hand from before 1 Aug, but I do know that 2008 had approx 900,000km/2 more sea ice extent than 2007 in late July, and that figure has now reduced in unprecedented fashion to…… hmmmmm…… drum roll please………….. approx 870,000km/2 as of yesterday! “Neck-and-neck” indeed….

As for whether the events of 4-7 August spelt something unprecedented for the rest of the month, well, there’s been some debate on here about about that ( :) AndyW!) Looks too early to call the moment, though I appear to be the arch-optimist in the debate lol

These are some quick calculations I just did of the recent daily 3-day average reduction rates for (1) sea ice extent (from JAXA) and (2) ice area (from CT)

(1) Sea ice extent daily 3-day average reduction rates

23-26 Jul 82,448 km/2 per day
26-29 66,927 km/2 per day
29-1 74,427 km/2 per day
1-4 Aug 86,458 km/2 per day
4-7 118,646 km/2 per day
7-10 49,896 km/2 per day

(2) Ice area daily 3-day average reduction rates

1-4 Aug 72,000 km/2 per day
4-7 193,000 km/2 per day
7-8* 20,000 km/2 per day

* results for 9th due out in a couple of hours

497. Chris
Posted Aug 11, 2008 at 7:04 AM | Permalink

#498 contd – hope this makes figures easier to read/compare:

(1) Sea ice extent daily 3-day average reduction rates

23-26 82,448 km/2 per day
26-29 66,927 km/2 per day
29-01 74,427 km/2 per day
01-04 86,458 km/2 per day
04-07 118,646 km/2 per day
07-10 49,896 km/2 per day

(2) Ice area daily 3-day average reduction rates

01-04 72,000 km/2 per day
04-07 193,000 km/2 per day
07-08 20,000 km/2 per day

498. Schnoerkelman
Posted Aug 11, 2008 at 7:04 AM | Permalink

Perhaps this is the help that Baby Ice needs?

There is a nice image here of Cleveland:

499. Posted Aug 11, 2008 at 7:05 AM | Permalink

Re #488

The ice forecast is really interesting – have you got the link?

The way to find it on a regular basis would be to go to the page below and scroll down for the 30 day Ice forecast.

Weather

But all the evidence suggests the interview was in the last couple of days: note the past tense in “triggered” (‘But the Beaufort Sea storms triggered steep ice losses and it now looks as if it will be a very close call indeed whether 2007 or 2008 is the worst year on record for ice cover over the Arctic…)

Bear in mind that The Observer is a weekly, I suspect that the interview was from the beginning of the week.

500. Posted Aug 11, 2008 at 7:10 AM | Permalink

Re #498-499

From the JAXA site:
Usually, sea ice extent is defined as an average of several days in order to eliminate calculation errors by data deficiency. However, we adopt the average of two days in this site for the purpose of rapid release.

501. Schnoerkelman
Posted Aug 11, 2008 at 7:29 AM | Permalink

Re #500
Sorry my links didn’t make the trip. Perhaps simple text.
Third Aleutian Volcano Erupts Explosively

Cleveland Volcano, Aleutian Islands

http://www.nasa.gov/multimedia/imagegallery/image_feature_756.html

502. Posted Aug 11, 2008 at 7:53 AM | Permalink

Re #503

Sorry my links didn’t make the trip. Perhaps simple text.

You need to put some descriptive text between the ‘Link’ and ‘slash-link’, then that text shows up as a clickable link.

503. Aaron Wells
Posted Aug 11, 2008 at 8:21 AM | Permalink

Here are my graphs for yesterday’s ice extent data.

Daily Arctic Sea Ice Extent Reduction Day 223

Arctic Sea Ice Extent Day 223

2008 Arctic Ice Extent Differences From Previous Years Day 223

504. DaveM
Posted Aug 11, 2008 at 8:26 AM | Permalink

Mr. Watts has an interesting piece here.

505. Pat Keating
Posted Aug 11, 2008 at 10:16 AM | Permalink

505 Aaron

It seems to be settling on the 2005 curve, now.

506. Aaron Wells
Posted Aug 11, 2008 at 10:36 AM | Permalink

The CT data is reported about 12hrs later than JAXA and seems to refer to the previous day (the map is so dated).

The new CT data is out:

area difference anomaly
Arctic
4.231 0.105 -1.635

Below is a graph comparing JAXA Ice Extent vs CT Ice Area for the past 11 days (I only have CT data for that long). I have shifted the CT data to the left 1 day, which seems to prove Phil’s point above.

CT vs JAXA (CT shifted 1 day to the left)

507. Aaron Wells
Posted Aug 11, 2008 at 11:20 AM | Permalink

I should have said that the graph in my previous post compared JAXA and CT area losses, not areas.

508. DeWitt Payne
Posted Aug 11, 2008 at 2:45 PM | Permalink

And for those interested in the Antarctic
from CT:
area difference anomaly
13.925 0.165 -0.099

Doesn’t look like a record setting pace, but it was about this time in 2007 that the Antarctic started it’s big push that achieved record or near record area.

509. Posted Aug 11, 2008 at 4:02 PM | Permalink

Just in:

http://www.physorg.com/news137678918.html

(PhysOrg.com) — While the summer of 2007 saw record low sea-ice coverage of the Arctic Ocean, a six-year study of the Arctic’s sea ice has confirmed its ongoing, massive shrinking and drastic thinning.
University of Alberta researcher Christian Haas, professor in the Department of Earth and Atmospheric Sciences and Alberta Ingenuity Scholar, has gathered a unique data set showing that the sea ice in the region of the North Pole has thinned up to 53 per cent between 2001 and 2007.

“The sea ice is becoming more vulnerable to further retreat, as ice thickness is very uniform over large regions, and ice reduction can be very fast once a certain threshold thickness is reached,” he said.

The results, published online in the Geophysical Research Letters, indicate that the North Pole might soon be ice-free in the summer.

——

must be very new, not yet listed on GRL at AGU’s website.

510. Ernie
Posted Aug 11, 2008 at 6:38 PM | Permalink

#506

That’s a very interesting article. I was not aware that there was decadal-scale changes in the circulation of the Arctic Ocean. I guess they haven’t been monitoring it for long enough for any degree of certainty, but it’s an interesting theory. Well worth keeping an eye on.

511. TAC
Posted Aug 11, 2008 at 9:05 PM | Permalink

Preliminary Unofficial Day 224 Race Report
2008 has a moderate day, slightly expanding its lead on 2005 and 2006.
8 12 2002 6.615938 -0.065937
8 12 2003 6.861563 -0.025468
8 11 2004 6.994531 -0.063282
8 12 2005 6.324063 -0.048906
8 12 2006 6.496719 -0.039531
8 12 2007 5.421094 -0.047500
8 11 2008 6.287813 -0.056093

512. Mike Bryant
Posted Aug 11, 2008 at 9:33 PM | Permalink

2008 is still closer to any other year in the group than it is to 2007.

513. Posted Aug 11, 2008 at 9:46 PM | Permalink

Re #514

2008 is still closer to any other year in the group than it is to 2007.

Which considering 2008 started ~1.0 higher than 2005 & 2007 is quite remarkable.

514. Chris
Posted Aug 12, 2008 at 1:04 AM | Permalink

I’m going to be pessimistic for once. There’s been high and increasing positive temperature anomalies in the northern Siberian region the last couple of days, looking to continue in the short term, and the daily ice comparison 10th-11th does not look good. The CT area reduction going back up to -0.10 could suggest increasing extent reductions in the short term as well (thanks Phil for the posts re: CT and JAXA average dates). I hope I’m wrong.

But I will add one happier thought. Remember this piece of history?

—————————
Steve McIntyre says:

July 2nd, 2008 at 9:28 pm

Day 183 (starting at 0) in the books. This was a very big day last year and 2008 fell behind another 100,000 sq km. Now over 600,000 sq km off the pace.

7 3 2007 8.925000 2007-07-03 13697 200707 183 -0.201875
7 2 2008 9.546406 2008-07-02 14062 200807 183 -0.098594

—————————————————————

Firstly note the -202,000 km/2 on 3rd July 2007 (this makes me feel better about the -140,000 km/2 last week and any more bad days which may be to come)

Secondly note that since then 2008 has gone from 620,000 off the pace then to 870,000 as of today. I’d say this could be seen as a remarkable feat by the baby ice in the peak melting season (#515)

515. Flanagan
Posted Aug 12, 2008 at 1:05 AM | Permalink

Phil: does that mean that 2008 has lost 0.133 more than 2007 at this date?

516. STAFFAN LINDSTROEM
Posted Aug 12, 2008 at 1:44 AM | Permalink

…Phil. and Flanagan…have you checked total VOLUME LOSS each
melting season
since 1950????? No!!! PERIOD – Because there are to this moment
no reliable even “guesstimations” of that, or??? Besides as
David Smith has pointed out earlier in this thread, I think,
the earlier in the season the ice melts the more important albedo-wise it
is. An almost complete arctic ice melting could even be beneficial
for albedo, granted the temperature is low enough. More snow
in the arctic region, and early. for example Kiruna in Sweden’s
N Lappland had 4 cm snow cover Aug 30 or 31 LAST year![Almost?
unprecedented]
Ever wondered why a “hot” period in earth’s climate history
is followed by a free fall of temperatures?? Be chilled,
very chilled…I want to hear from an expert of the latest NH
glaciation, could the arctic ocean have been icefree in the summer
so the ice-sheets melted from the north too??…

517. Flanagan
Posted Aug 12, 2008 at 2:21 AM | Permalink

Hello there,

in post 511 you can find a link showing that not only the extent but also the thickness of the arctic sea ice is decreasing – which could be some hint about what is happening to the volume :0) What happens to the albedo is something else and is related also to where the melt is occuring and, of course, to what happens in the SH. Very complex topic, which I believe is not the subject here.

518. MJW
Posted Aug 12, 2008 at 2:38 AM | Permalink

Phil.:

Which considering 2008 started ~1.0 higher than 2005 & 2007 is quite remarkable.

One might also consider it quite remarkable that given the melting in 2007, 2008 started out ~1.0 higher than 2005 & 2007.

519. STAFFAN LINDSTROEM
Posted Aug 12, 2008 at 3:09 AM | Permalink

#511 Leif, having your inverted initials and also been
to Sinaia [pronounced SHE-NIA approx.[ROMANIA]] back in 1970…
The Phys.org has an ad for icebreaker tours in June
and July 2008…22.900 USD…a BARGAIN!?[Should have an update] But that must
be “Yamal or any of the other russian nuclear arctic class1
ice-breakers. The research ice-breaker “Polarstern” probably
will not make it all the way to the NP this summer either,
last summer she reached 88.7N! According to WIKI “Polarstern
can break 1,5 m thick ice at 5 knots. Check her Ship history
dump since January 1 2003!! This summer up to 82.4N …
Thicker ice can be broken by ramming but not for any long distances
So I/B “Polarstern” may be an indicator of ice thickness coming
from the N Atlantic.

520. STAFFAN LINDSTROEM
Posted Aug 12, 2008 at 3:14 AM | Permalink

#520 Correcting my self, sorry Phys.org SHOULD BE:
PhysOrg.com!!

521. Chris
Posted Aug 12, 2008 at 3:32 AM | Permalink

#515 etc

We need to distinguish between two types of first year sea ice:

(1) The furthest flung ice floes at the end of winter. These vanished away, almost in a puff of smoke, in mid-April when 2008 went from 700,781 km/2 ahead of 2007 to 195,157 ahead in 10 days (10th-20th April). And this was nothing unusual c.f. 2003.

(2) The ice which reformed in the areas exposed as water during the exceptional 2007 summer melt. These have stubbornly refused to melt as predicted since April. The lead of 2008 over 2007 since then has been as follows:

April 20th: 195,157 km/2
June 20th: 909,532 km/2
August 11th: 866,719 km/2

I think it is very important that these simple truths are not lost in the current hysteria over a few days fast melting (even if we have quite a few more such days.)

522. Chris
Posted Aug 12, 2008 at 3:40 AM | Permalink

Further note re: #522

“ahead” and “lead” referred to absolute sea ice extent, rather than its reduction. The terminology here is a minefield………………

523. Posted Aug 12, 2008 at 8:08 AM | Permalink

Re #518

have you checked total VOLUME LOSS each
melting season
since 1950????? No!!! PERIOD – Because there are to this moment
no reliable even “guesstimations” of that, or???

“The rate of decrease of sea ice thickness and volume possibly about 2x greater than that of sea ice extent.”

Between 97 and 04
“annual mean sea ice concentration has decreased by ~17%
mean ice thickness has decreased by ~0.9 m or ~36%
ice volume decreased by 40%, which is more than 2x the rate of ice area decrease”

524. DeWitt Payne
Posted Aug 12, 2008 at 8:38 AM | Permalink

It’s not at all surprising to me that ice volume has decreased since the mid 1990’s. All you have to do is look at the MSU temperature data for 60 to 82.5 or NoPol from RSS and UAH or 20 to 82.5 or NoExt. The temperature increase has been substantial. But is this AGW or a shift in ocean currents that eventually reverses or some combination of both? That is still an open question. Smoothed plots of NoPol anomalies show evidence that temperatures may have peaked last year and the plots of the Atlantic MOC and it’s lagging correspondence with the NAO lend credence to the ocean current shift hypothesis.

Small upward correction in the JAXA data to 6.291563 Mm2. Have we finally seen the bottom of the rate curve? I’m still projecting 5.3 Mm2 on 9/15 as the minimum extent.

525. Aaron Wells
Posted Aug 12, 2008 at 8:58 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data.

Daily Arctic Sea Ice Extent Reduction Day 224

Arctic Sea Ice Extent Day 224

2008 Arctic Ice Extent Differences From Previous Years Day 224

526. Posted Aug 12, 2008 at 9:23 AM | Permalink

Re #526

It’s not at all surprising to me that ice volume has decreased since the mid 1990’s. All you have to do is look at the MSU temperature data for 60 to 82.5 or NoPol from RSS and UAH or 20 to 82.5 or NoExt. The temperature increase has been substantial. But is this AGW or a shift in ocean currents that eventually reverses or some combination of both? That is still an open question. Smoothed plots of NoPol anomalies show evidence that temperatures may have peaked last year and the plots of the Atlantic MOC and it’s lagging correspondence with the NAO lend credence to the ocean current shift hypothesis.

From my perspective it seems illogical to completely separate AGW and shifts in ocean currents, changing the energy balance/distribution of the atmosphere must effect to some extent the winds and currents at the surface.
Regarding temperature anomalies in the Arctic, essentially it’s no difference than plotting ice area, at this time of year you get a large positive anomaly wherever there is open water where normally there is ice. Regarding ocean currents, if we’re in a cooling PDO phase that means we will have a positive temperature anomaly in the N Pacific which is likely to promote melting.

Re #517

Right now on area they’re fairly close (~10.0 loss), so with a month to go the odds favor ’08 becoming the largest melt of the satellite era, I’ve not looked at the extent stats.

527. Posted Aug 12, 2008 at 9:54 AM | Permalink

Phil #528,

changing the energy balance/distribution of the atmosphere

and what changes in the distribution of energy some well mixed GHGs are causing?

528. Aaron Wells
Posted Aug 12, 2008 at 11:12 AM | Permalink

Right now on area they’re fairly close (~10.0 loss), so with a month to go the odds favor ’08 becoming the largest melt of the satellite era, I’ve not looked at the extent stats.

I have examined JAXA’s ice extent data and for each year since 2003, compared today’s extent value to the ice extent peak and calculated a maximum reduction from peak. The following are the results:

$Year DropFromPeak OtherYearMinus08 2008: 8225312 (peaked at 14,516,875 on 3/09/08) 2007: 8524531 299219 (peaked at 13,935,156 on 3/10/07) 2006: 7285625 -939687 (peaked at 13,782,344 on 3/11/06) 2005: 7774843 -450469 (peaked at 14,098,906 on 3/06/05) 2004: 7365782 -859530 (peaked at 14,360,313 on 3/10/04) 2003: 7982500 -242812 (peaked at 14,844,063 on 3/21/03)$

So, according to JAXA data, 2008 trails 2007 in drop from peak as well, by 299,219 km^2.

529. Aaron Wells
Posted Aug 12, 2008 at 11:13 AM | Permalink

Let’s try that again:

Right now on area they’re fairly close (~10.0 loss), so with a month to go the odds favor ’08 becoming the largest melt of the satellite era, I’ve not looked at the extent stats.

I have examined JAXA’s ice extent data and for each year since 2003, compared today’s extent value to the ice extent peak and calculated a maximum reduction from peak. The following are the results:

Year DropFromPeak OtherYearMinus08
2008: 8225312 (peaked at 14,516,875 on 3/09/08)
2007: 8524531 299219 (peaked at 13,935,156 on 3/10/07)
2006: 7285625 -939687 (peaked at 13,782,344 on 3/11/06)
2005: 7774843 -450469 (peaked at 14,098,906 on 3/06/05)
2004: 7365782 -859530 (peaked at 14,360,313 on 3/10/04)
2003: 7982500 -242812 (peaked at 14,844,063 on 3/21/03)

So, according to JAXA data, 2008 trails 2007 in drop from peak as well, by 299,219 km^2.

530. DeWitt Payne
Posted Aug 12, 2008 at 11:16 AM | Permalink

Phil,

From my perspective it seems illogical to completely separate AGW and shifts in ocean currents, changing the energy balance/distribution of the atmosphere must effect to some extent the winds and currents at the surface.

I’ll spell it out. Has the energy balance/distribution changed permanently because of AGW or is this just a phase similar to what was seen in the first half of the twentieth century? Will ice volume loss continue or not? If you don’t attempt to separately account for the effect of AGW, you are begging those questions.

531. DeWitt Payne
Posted Aug 12, 2008 at 11:23 AM | Permalink

Area changes very close to average for the date:
From CT
region area difference anomaly
Arctic 4.185 -0.046 -1.631
Antarctic 14.001 0.076 -0.099

532. Aaron Wells
Posted Aug 12, 2008 at 11:37 AM | Permalink

Phil, you seemed to be very concerned about the reduction from peak. Hear is a graph of the reductions from peak (in km^2)for years 2003-2008:

Drop From Peak in km^2 for past 3 weeks

It really doesn’t look like 2008 will catch 2007 in maximum reduction from peak based upon the past 3 weeks data.

533. Stephen Wilde
Posted Aug 12, 2008 at 11:47 AM | Permalink

Aaron,

Can you describe how you create your charts and where you get the details from for inclusion ?

The following link seems to be giving a different slant on things and I don’t know which to give most credence to:

534. Stephen Wilde
Posted Aug 12, 2008 at 11:50 AM | Permalink

Hope this works better.

535. Chris
Posted Aug 12, 2008 at 11:52 AM | Permalink

Dewitt and Phil:

RE: NoPol temperature anomalies c.f. my post above at #405. I’ll just re-paste the last part of it i.e. NoPol anomalies averaged for June and July since 2000 (my earlier post also includes the figures for 1988-1999 when the figures were generally significantly lower)

2000 0.27
2001 0.68
2002 0.79
2003 0.85
2004 0.53
2005 1.04
2006 0.83
2007 1.47
2008 0.52

I agree with DeWitt insofar as summer temperatures show a marked drop from last year (-0.95C). But I agree with Phil insofar as, given this, the melt seems to have been relatively large, showing at least some knock-on effect from 2007.

Where I may be more optimistic than Phil is in the prognosis for the rest of the season. If 2008 in the Arctic continues to be cooler than in 2007, as I suspect, then we ought to see freezing temperatures spreading progressively southwards at earlier dates than last year. Certainly the last week shows evidence of such a spread: http://www.cdc.noaa.gov/map/images/fnl/sfctmpmer_01.fnl.anim.html. (though I don’t have data to compare for last year)

So even if the ice keeps melting in the Siberian seas (or in other peripheral areas for that matter) due to localised heatwaves, and bringing the extent figures down relatively fast, I think conditions may be more favourable for area to stop declining as quickly as in 2007, since the main concentrations of ice are closer to the pole and any increased fragmentation could even allow more scope for early re-freezing/consolidation.

As for AGW theory, I agree with Phil that AGW and the strong AMO/NAO/AO since the 1990s *could* be related. However, AGW theory seems to use aerosols to explain the temperature dip after the 1940s (while apparently ignoring PDO) and as far as I can see does not rely on AMO/NAO/AO as mechanisms for warming the north polar regions (although of course it did predict warming skewed towards the poles). Thus, if the north polar region continues to cool, and the ice continues to recover (albeit with a lag), while ocean currents shift to cool phases, this could be tricky for AGW theory. I take Phil’s point about PDO cool phase bringing warmer temperature anomalies to the N Pacific (like now, feeding through on the SE winds to Siberia). But PDO cool phase is also associated with more La Nina/less El Nino i.e. less heat transfer to north polar region overall (summer 08 NoPol temperature anomalies a case in point?). As for AMO/NAO/AO, until a shift to cool phase happens, it will be hard to test the effects unfortunately.

I think a lot hinges on whether the recent La Nina marked a step change downwards in temperature as a converse to the 1998 El Nino, or whether it was just a blip in a warming trend. That’s why I’m very interested to see what ENSO does this winter, and what happens to Hadley Global SSTs (HadSST2) which appeared to be in a steady annual decline (from a mid-decade peak) until they made up significant ground last month http://www.cru.uea.ac.uk/cru/data/temperature

536. Chris
Posted Aug 12, 2008 at 11:57 AM | Permalink

Here’s the first link again without the full stop at the end:

http://www.cdc.noaa.gov/map/images/fnl/sfctmpmer_01.fnl.anim.html

537. Chris
Posted Aug 12, 2008 at 12:16 PM | Permalink

Aaron:

(1) Note my post at #523 above. You could make an even stronger argument re: extent by starting from late April i.e. when the melt of thicker ice starts to occur, following the initial rapid melt of fleeting late winter ice floes (which happened to be spread over a large extent last winter)

(2) It appears that similar arguments apply re: area (see http://arctic.atmos.uiuc.edu/cryosphere/iphone/iphone.currentarea.series.html ) Does anyone know how to get hold of the daily figures?

Of course making these arguments means accepting that the winter 2007/8 extent and area peaks were not so special as some like to make out :)

Otherwise, I think Phil’s arguments about area reductions seem fair based on trends to this point….. (though see #537 re: the rest of the season)

538. Chris
Posted Aug 12, 2008 at 12:18 PM | Permalink

For anyone who’s not clear about the value of extent vs area, Phil summed it up helpfully at #304 in the original Sea Ice thread:

“The extent sums the area of all the pixels that show an ice concentration of greater than 15% whereas the total area is the sum of the pixel area times the concentration, area is necessarily less than extent but there is no fixed relationship between them. You could have a case where the ice wasn’t fragmented and area and extent were very similar, or a large extent of very broken uo ice at low concentration, in which case the area would be very much less than the extent.”

539. DeWitt Payne
Posted Aug 12, 2008 at 12:33 PM | Permalink

Chris,

A quick check shows that if you don’t include 2007 there is no correlation between minimum extent and temperature anomaly, either my smoothed or your 2 month average. David Smith (IIRC) had a post a while back that showed a possible correlation of SST in September of the previous year with ice extent or area which predicted that this year’s ice would be back in the normal range, but I can’t find it.

540. Aaron Wells
Posted Aug 12, 2008 at 12:49 PM | Permalink

Can you describe how you create your charts and where you get the details from for inclusion ?

As I noted in #531, all of my ice extent area data comes from IARC/JAXA, who updates their information daily at this site:

Data of Sea Ice Extent

Basically, I did an initial data download from the “Data Download” button on that page a couple of months ago, and started a spreadsheet that I maintain with all of my graphs. I check that page daily for the 2008 daily updates.

The following link seems to be giving a different slant on things and I don’t know which to give most credence to:

NSIDC uses slightly different data, and they don’t offer the data in a very convenient format. You can download the data from NSIDC, but it is in binary format that only their tools know how to read, and I have not found any documentation that explains the binary format so that I could convert it to text. The link to the NSIDC binary data is Near Real-Time DMSP SSM/I Daily Polar Gridded Sea Ice Concentrations and Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I Passive Microwave Data

Why NSIDC and IARC/JAXA have slightly different ice extent data, I don’t know. I would plot NSIDC data if their format were more convenient to convert to spreadsheet.

NSIDC has a history of a couple of occasions doing a drastic downturn in the chart that you mentioned. Up until a day or two, their graph was showing a leveling off, but then one day in the past day or two it turned downward sharply. As you noted, the IARC/JAXA data does not show the same sharpness in downturn.

On one previous downturn of their graph, I noted the severity on this blog, and Steve suggested that I contact NSIDC and ask them about it. I did so with the following email:

To whomever maintains the N_timeseries.png graph,

I noticed that the downturn currently at the end of the Arctic Sea Ice Extent appears to be slightly excessively steep. I track the arctic ice extent data using IARC/JAXA data, and don’t see such a steep decline. According to their data it would take nearly 7 days of the recent extent reduction to lose that much area, but the x-axis domain during that decline appears to be much less than that.

Could you kindly share with me the data that you use to produce that graph, please?

Your assistance will be greatly appreciated.

Aaron Wells

A Donna Scott from NSIDC very promptly responded with the following:

Dear Mr. Wells,

NSIDC uses our Sea Ice Index product to derive this graph. You can see this product at http://nsidc.org/data/seaice_index. The product is derived from the following data sets:

Near Real-Time DMSP SSM/I Daily Polar Gridded Sea Ice Concentrations http://nsidc.org/data/nsidc-0081.html
and
Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I Passive Microwave Data http://nsidc.org/data/nsidc-0051.html

As for the trend in the graph, one of our sea ice Scientists thinks the downward turn we’re seeing is real. AMSR-E data also show much reduced sea ice concentrations.
There’s a strong low pressure system that is over the Beaufort that has been fostering ice divergence, and now also seems to be favoring mechnanical breakup and melt through advection of heat. We expect to see a sudden downward trend in the ice extent.

Let me know if you have further questions.

Best regards,
Donna Scott
NSIDC User Services

This exchange occurred about a week ago.

541. DeWitt Payne
Posted Aug 12, 2008 at 12:57 PM | Permalink

Chris,

I found the relevant post, but forgot he had withdrawn it because the significance of the lagged vs. concurrent correlation again depended largely on one point, 2007.

542. Stephen Wilde
Posted Aug 12, 2008 at 1:20 PM | Permalink

543. Chris
Posted Aug 12, 2008 at 1:43 PM | Permalink

DeWitt: I think the talk of correlations distracts from the main focus of what I was saying. I only quoted the figures in #537 because:
(1) they might be of interest to people in any event (they show summer so far in the polar regions has been on average the coolest since 2000 – narrowly beating 2004)
(2) in order to introduce the 1C drop from summer 07 to summer 08, which is a factor in my discussions.

I wasn’t setting out to show any correlations (Though now you mention it, 2005 is the next warmest after 2007 and also had the next lowest extent, which goes against what you say in #541 somewhat)

544. Aaron Wells
Posted Aug 12, 2008 at 7:09 PM | Permalink

Is it just me, or has NSIDC levelled off their graph again after having a sharp downturn for the past day or 2?

Here is their latest sea ice extent graph (distinctly levelled off).

Today’s latest update

Now here is yesterday’s graph, which was part of their regular update about how ominous the situation is for the baby ice:

If you load these 2 images in 2 different browser tabs and switch back and forth, you see an animation-like swinging of the end of the graph.

Could this be because of their smoothing method?

545. Aaron Wells
Posted Aug 12, 2008 at 7:12 PM | Permalink

Let’s try it again. The second link didn’t work. I guess I forgot to close the link.

Today’s latest update

Yesterday’s graph

546. Aaron Wells
Posted Aug 12, 2008 at 7:17 PM | Permalink

Do an a poor-man’s animated gif….

Click on the 1st link above, then copy the URL. Then hit the back-button, click on the 2nd link. That will bring up yesterday’s NSIDC graph. With that page loaded, then paste the URL from the 1st graph into the URL address field in your browers. Then hit the back and forth buttons on your browser. You’ll see the end flip back and forth.

547. TAC
Posted Aug 12, 2008 at 9:09 PM | Permalink

Preliminary Unofficial Day 225 Race Report
2008 has another moderate day, holding its small lead on 2005 and 2006.
8 13 2002 6.549531 -0.066407
8 13 2003 6.804531 -0.057032
8 12 2004 6.905313 -0.089218
8 13 2005 6.294688 -0.029375
8 13 2006 6.456875 -0.039844
8 13 2007 5.379219 -0.041875
8 12 2008 6.222500 -0.069063

548. DeWitt Payne
Posted Aug 12, 2008 at 9:29 PM | Permalink

2004 and 2006 at 5.78 Mm2 are now outside the 95% upper confidence limit of 5.76 Mm2. Only 2005 at 5.31 and 2002 at 5.64 Mm2 are still in play with 2008 projected at 5.3 Mm2 on 9/15. 2002 is just below the 90% upper confidence limit so it should drop out any day now. Five days now of decreasing smoothed extent loss rate.

549. bender
Posted Aug 12, 2008 at 9:47 PM | Permalink

#550 A 95% confidence interval has a 95% chance of containing the true population mean. It does NOT have a 95% chance of bracketing the next observation. (This is a very common mistake.) The latter is what is called the “prediction interval” and it is wider than the confidence interval. You should be calculating prediction intervals, not confidence intervals. You will then find there is a higher probability that 2008 will catch 2007.

550. Posted Aug 12, 2008 at 10:01 PM | Permalink

Re #534

Phil, you seemed to be very concerned about the reduction from peak.

Not really, but you can’t say that (as some have) it’s been cooler and that’s led to a lesser melt, the total melt for 08 is comparable (based on area) with 07.

Estimated area range data for 07: 13.4 – 3.0 = 10.4
Estimated area range data for 08 (so far): 13.9 – 4.2 = 9.7

So another 0.7 of melt to equal last year’s total melt which wouldn’t be unreasonable.

Re #532

If you don’t attempt to separately account for the effect of AGW, you are begging those questions.

Agreed, that was my point, but you can’t just assume that there’s no crosstalk!
How would you separate the two?

551. Posted Aug 12, 2008 at 10:16 PM | Permalink

Re #549

2008 has another moderate day, holding its small lead on 2005 and 2006.

8 13 2005 6.294688 -0.029375
8 13 2006 6.456875 -0.039844
8 13 2007 5.379219 -0.041875
8 12 2008 6.222500 -0.069063

In my math 0.069063 is greater than 0.039844 & 0.029375 which means that 2008 increased its lead on 2005 & 2006!

552. bender
Posted Aug 12, 2008 at 10:33 PM | Permalink

#552

you can’t just assume that there’s no crosstalk!

Yes. This is a favorite trick of the false skeptic (à la Andrew), to insist that one remove the noise (PDO, ENSO etc.) BEFORE you address the signal. The reality is that under AGW there ought to be some confounding of the two. And as external signal and internal noise interact (“crosstalk”) you end up with noisy signal. This is THE unsolved problem in attribution, IMO.

[Reminiscent of the familiar false dichotomy: nature vs. nurture. Or, more precisely, the additive model: nature + nature. (The reality is nurture conditions nature, leading to a multiplicative interaction term in the model.)]

553. DeWitt Payne
Posted Aug 12, 2008 at 11:05 PM | Permalink

bender,

I looked up prediction interval and the additional factor is sqrt(1+1/n)Ta or 1.08Ta for n=6. Of course I’m probably doing it wrong. If I were predicting the extent for the next day, which I’m not, the range would be a smaller and then expand for each additional day of projection. I think what I’m doing shortcuts that, but who knows. Considering that the average extent left to lose is less than 1 Mm2 at this point, a range of +/- 0.5 Mm2 on the projected minimum seems reasonable. As I said when I started this, I’m not at all sure what I’m doing. Criticism is welcome, but it would help if it were more specific. I’ve detailed above what I’m doing. Suggestions?

554. AndyW
Posted Aug 13, 2008 at 12:34 AM | Permalink

Interesting how the NSIDC graph has been corrected so much.

Looking at 2007 there was only 4 days above 60k loss and 0 above 70k, I sort of expect the same sort of reducing amounts for this year even though the peak loss time span was a lot broader and was near the top quite recently. Unless there is a dramatic change I think 2008 will pull away quite comfortably from 2006 and 2005, though my minima of 5M km^2 is probably too low now. As it’s such a nice round number I will inscientifically keep it as my guess though.

Some enlightening posts above this one, great to read.

555. Flanagan
Posted Aug 13, 2008 at 1:15 AM | Permalink

Well, maybe some of you noticed that within 5 days only, a lot of the ice has gone to concentrations being barely 40-50%. This is especially striking in the North of Russia and Canada. Can any1 tell me whether the current insolation could be sufficient to melt all these regions?

556. Chris
Posted Aug 13, 2008 at 2:04 AM | Permalink

#557: North of Russia – quite likely (see my previous posts, though this is increasingly more down to warm winds/water than sun)

Canada – mostly too cold (see http://wxmaps.org/pix/temp2.html – sub-zero temperatures set to continue in region down to 75 degrees N for next 2 weeks; and http://www.weatheroffice.gc.ca/data/analysis/jac06_50.gif – the cold snap has been brought by a strong sustained plunge of northerly winds straight from the north pole. In fact if you look closely at your satellite comparison you can see how some of the apparent thinning in northern Canada is actually the result of the winds spreading the sea ice southwards.

557. Chris
Posted Aug 13, 2008 at 2:22 AM | Permalink

The following should make it even clearer why I’ve been so much more concerned about the seas north of Siberia than anywhere else! It’s from 6 o’clock GMT today i.e. mid-this-afternoon in Siberian time http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/arcisoTTPPWW.gif
Note how the 20C temperature line goes past a large swathe of the Siberian coast…….

558. Flanagan
Posted Aug 13, 2008 at 2:45 AM | Permalink

Thanks Chris!

559. Chris
Posted Aug 13, 2008 at 4:45 AM | Permalink

No problem.

Also note that the NSIDC – 11th Aug http://nsidc.org/arcticseaicenews/ – confirmed what I’ve been saying about the southerly winds since last week:

“…a pattern has developed with high pressure over the Beaufort Sea and low pressure over the Laptev and East Siberian Seas (Figure 3). In accord with Buys Ballot’s Law, this pattern has brought southerly winds to the region, enhancing melt, breaking up ice, and pushing the ice edge northward…”

This pattern was exceptionally strong early last week, moderated from the second half of last week, and is now peaking again. Thus area/extent reductions could easily go high again in the next couple of days.

The weather history and forecasts for Tiksi on the Laptev coast are great for understanding how this is happening on the ground http://www.weatheronline.co.uk/RussianFeder/Tiksi.htm
There is some good news in that NE winds appear to be setting in there from tomorrow night.

560. TAC
Posted Aug 13, 2008 at 5:25 AM | Permalink

Phil. (#553):

In my math 0.069063 is greater than 0.039844 & 0.029375 which means that 2008 increased its lead on 2005 & 2006!

Phil., have you turned into another Annoying Auditor? Do you expect me to use your old-fashioned math? I thought you were different, Phil.; I thought you respected new mathematical approaches.

Have you thought this through? Do you know where this might lead? Imagine if your standards got applied to the entire field — are you trying to ruin it for everyone?

Some people just don’t get it.
;-)

561. Posted Aug 13, 2008 at 10:23 AM | Permalink

Today the sea ice area hit 4.1 Mm^2, therefore it’s already ~equalled the minimum for all years except 2007.

562. Stephen Wilde
Posted Aug 13, 2008 at 11:21 AM | Permalink

The graph in post 563 is way out of line with the charts from Aaron and also from NSIDC. Why is that ?

Neither of the others are down to 6 million square kilometres yet.

563. Posted Aug 13, 2008 at 11:28 AM | Permalink

Re #564
Because it’s ice ares see here for example.

564. UK John
Posted Aug 13, 2008 at 12:24 PM | Permalink

#563 Phil, since 1979 not all years!

565. DeWitt Payne
Posted Aug 13, 2008 at 1:16 PM | Permalink

Phil,

it’s already ~equalled the minimum for all years except 2007.

But that’s not news. The extent will also very likely be below all years starting from 2002 with the possible exception of 2005. How close will 2008 minimum area be to 2007? Who knows. I haven’t been able find enough data to make an empirical prediction. The area anomaly hit -3 Mm2 in 2007, ~1.5 Mm2 lower than any previous year, and it’s -1.7 now. Will the 2008 anomaly reach 2007 levels? Again, who knows. For anyone without access to all the historical data, a projection of the 2008 minimum is nothing more than speculation.

Antarctic area had a big day:
14.199 0.198 0.025

That’s a change in the anomaly of +0.124 Mm2.

566. DeWitt Payne
Posted Aug 13, 2008 at 1:40 PM | Permalink

I took away a degree of freedom and calculated 99% prediction intervals (+/- 5.06*s.d., n=5 df=4). 2007 is still below the lower prediction limit. So the probability of 2008 catching 2007 is higher with this assumption, but it’s still pretty small, less than 0.5% I think.

567. bender
Posted Aug 13, 2008 at 1:54 PM | Permalink

#568 Fair enough. Just thought I would give you a leg up on your competitors in the prediction game.

568. Posted Aug 13, 2008 at 2:55 PM | Permalink

Re #567

But that’s not news. The extent will also very likely be below all years starting from 2002 with the possible exception of 2005.

That you don’t think it’s newsworthy that this year’s melt has reached or surpassed the minimum of all those years with ~month to go shows what a remarkable situation we have in the Arctic.

How close will 2008 minimum area be to 2007? Who knows. I haven’t been able find enough data to make an empirical prediction. The area anomaly hit -3 Mm2 in 2007, ~1.5 Mm2 lower than any previous year, and it’s -1.7 now. Will the 2008 anomaly reach 2007 levels? Again, who knows. For anyone without access to all the historical data, a projection of the 2008 minimum is nothing more than speculation.

Beware relying on the anomaly it can lead you astray! The anomaly at the minimum was ~-2Mm^2 so the current value is only ~0.3 off, the increase to -3Mm^2 was because of the late start to the freeze cycle, the curve shows that this starts around the 2nd week of Sept instead of which it lagged significantly and didn’t start to catch up until the 3rd week of Oct.

569. Philip_B
Posted Aug 13, 2008 at 3:24 PM | Permalink

Re #570

You are right. The drop in the anomaly from -2M to -3M wasn’t caused by exceptional melt. It was caused by exceptional failure to freeze from around mid-september to mid-october. It will be another 2 months before we know if the same thing occurs this year.

570. DeWitt Payne
Posted Aug 13, 2008 at 4:14 PM | Permalink

Phil,

Do you have the minimum areas for the last 15 years? What’s the mean, standard deviation, trend slope and correlation coefficient? Without that information it’s impossible to say whether this year’s minimum will be unusual or not. Let’s look at extent where I do have data. The mean minimum extent for 2002 to 2005 is 5.71 Mm2. Calculating 90% prediction limits gives UL 6.32 and LL 5.11. So if the actual minimum is inside that range it can’t be considered out of the ordinary. 2007, OTOH was way outside the range and probably qualifies as an outlier.

The next question, is there a trend? 5 years isn’t really enough, but it’s all I’ve got so the trend is -0.045/year but the R2 is only 0.08 so it’s not very significant. Still, using the trend line 2008 should have a minimum extent of 5.53. That would make an extent of 5.3 for 2008 a little low, but not unusually low especially considering the uncertainty in the slope and intercept of the trend line.

The last question is: if there is a trend downward, will it continue, accelerate, flatten out or reverse? On that point, it’s anybody’s guess. The Arctic area anomaly plot since 1979 looks to me like an inverted MSU Arctic temperature anomaly plot. But that’s just eyeball. I don’t have the data to do an analysis.

571. DeWitt Payne
Posted Aug 13, 2008 at 4:14 PM | Permalink

That’s 2002 to 2006 not 2005.

572. bender
Posted Aug 13, 2008 at 4:22 PM | Permalink

the R2 is only 0.08 so it’s not very significant

“Significance” is assayed by the p-value on your R2, not the R2 itself. I mentioned that earlier this week in the Amman thread. Even with 5 points it is possible an R2 of 0.08 is 95% significant.

573. DeWitt Payne
Posted Aug 13, 2008 at 4:36 PM | Permalink

bender,

My gut feeling was correct, the p value for the slope is 0.65 and the 95% confidence interval on the slope, -0.33 to 0.24 includes zero. If I include 2007, the slope is much more negative and the projected 2008 minimum is above the trend line, but the p value is 0.133 and the 95% confidence intervals on the slope still include zero. Insufficient data.

574. bender
Posted Aug 13, 2008 at 4:46 PM | Permalink

If 2009 is as low as 2008 would it be significant? I bet it would.

575. markinaustin
Posted Aug 13, 2008 at 7:11 PM | Permalink

what about the thickness question raised earlier in this thread? do we have any solid evidence for this?

576. Posted Aug 13, 2008 at 7:32 PM | Permalink

Re #572

Do you have the minimum areas for the last 15 years? What’s the mean, standard deviation, trend slope and correlation coefficient? Without that information it’s impossible to say whether this year’s minimum will be unusual or not. Let’s look at extent where I do have data. The mean minimum extent for 2002 to 2005 is 5.71 Mm2. Calculating 90% prediction limits gives UL 6.32 and LL 5.11. So if the actual minimum is inside that range it can’t be considered out of the ordinary. 2007, OTOH was way outside the range and probably qualifies as an outlier.

The data’s on the graph I posted here, there’s about 30 years worth. Eyeballing I’d say the mean of the mins is ~4.9 ±0.4, 2007 was a step outside that range (~5 sd) and 2008 is well on the way too.

577. Jim Arndt
Posted Aug 13, 2008 at 7:37 PM | Permalink

Ok all of you stats guys need to help me. 2007 is a record low for from the mean 1979 to present correct? Now 1979 is the starting point for a positive PDO. What is the standard deviation for half of a cycle from the mean? What I am saying is that should you not at least take the positive and negative PDO data at the very least to determine the mean? How many cycles do you need to get a “good” mean. Then there is the dark horse of AMO. Which is better or combine AMO or PDO? We take nearly 30 years of satellite ice data and say this is a record but can’t accept 29 years of satellite temperature data. I hope this makes sense.

578. Posted Aug 13, 2008 at 7:42 PM | Permalink

Re #577

what about the thickness question raised earlier in this thread? do we have any solid evidence for this?

Help us out here, which thickness question?

579. markinaustin
Posted Aug 13, 2008 at 8:31 PM | Permalink

the thickness of the ice may be far more significant than the area extent no?

or did i misunderstand the link by STAFFAN LINDSTROEM in 521.

580. TAC
Posted Aug 13, 2008 at 9:05 PM | Permalink

Preliminary Unofficial Day 226 Race Report
2008 has a relatively big day, increasing its lead on 2005 and 2006.
8 14 2002 6.461094 -0.088437
8 14 2003 6.741875 -0.062656
8 13 2004 6.822813 -0.082500
8 14 2005 6.251719 -0.042969
8 14 2006 6.404063 -0.052812
8 14 2007 5.347813 -0.031406
8 13 2008 6.130781 -0.091719

581. DeWitt Payne
Posted Aug 13, 2008 at 10:12 PM | Permalink

I would rather have the digital data, but picking points off the graph, there is a significant trend with a slope of -0.0581 Mm2/year 95% LL -0.0737 UL -.0425. The s.d. of the residuals is 0.118 so 2007 was about 8 s.d. from the trend line. The trend line has a value of 3.90 for 2008 with a 95% LL of 3.65. With n=28, prediction limits are less than 2% greater than confidence limits. It seems highly probably at this point that 2008 will be significantly below the lower confidence limit. I don’t have the tools to factor in possible autocorrelation. I don’t have the daily loss rate data to be able to do a better estimate of the minimum area for 2008. I can pick max and min off the graph, but that’s all.

582. STAFFAN LINDSTROEM
Posted Aug 13, 2008 at 10:43 PM | Permalink

# …help us out … Ice Bond comes to your assistance
…What about Polyakov et al :

http://www.frontier.iarc.uaf.edu:8080/~igor/research/pdf/ice.pdf

…Phil. Enjoy!!??

583. AndyW
Posted Aug 13, 2008 at 10:44 PM | Permalink

The intial loss for yesterday is over 90k and that is a very large loss compared to this time of year since 2002. 1million Km^2 has been lost since 1st August which is also a record. The thin ice and the warm weather mentioned by Chris seem to be really broadening out into a plateau the melt rate compared to previous years. I am looking forward to Aaron’s next graph.

I wonder how long it will last and how the end of NSIDC’s main graph will be reacting to this? Probably brewers droop followed by a small corrective erection!

584. STAFFAN LINDSTROEM
Posted Aug 13, 2008 at 11:34 PM | Permalink

#525,584 …Apparently, Staffan, there was even some
perhaps a little more than anecdotal evidence on the
Russian/Soviet/Russian side of the Arctic ocean, only
natural as at least parts of the Northeast Passage has
been open since at least late 19th century…

ADDENDUM 584 NOTA BENE: VR [WR] and CH ice thickness diagrams
PDF files…]

Phil. … There is also, especially for you, a PDF on
Arctic climate and GW…[Sorry NOT AGW, the Russians are not
too impressed by AGW theory, there are surely exceptions]

585. Flanagan
Posted Aug 14, 2008 at 12:26 AM | Permalink

Hello TAC,

I understand that you try to be as neutral as possible, but please do not call “relatively big” a melt which is more than the double of what it was for the closest past sea ice extent at the same time. Interesting also to note the percentage of extent lost on that day:
2008 – 1.5%
2007 – 0.6%
2006 – 0.8%
2005 – 0.7%
2004 – 1.2%
2003 – 0.9%
2002 – 1.4%

586. Chris
Posted Aug 14, 2008 at 1:56 AM | Permalink

Give it a couple of days, and may the fightback begin…………….

AndyW: 2004 ice extent reduction Aug 1st-13th = 7859688-6822813 = 1,036,875 km/2

…whereas… 2008 ice extent reduction Aug 1st-13th = 7100938-6130781 = 970,157 km/2

So your “record” (#585) is not even for the last 5 years……nor is it even over a million km/2 yet for that matter.

08,01,2004,7859688
08,13,2004,6822813

08,01,2008,7100938
08,13,2008,6130781

587. Chris
Posted Aug 14, 2008 at 2:55 AM | Permalink

#587: just to note that you can get a million for Aug 08 as well if you include the reduction of 1st Aug over 31 Jul – this is a moot point as the average date JAXA figures refer to is about a day earlier than the nominal date (see #502/#508 above) so I would say technically you shouldn’t include it.

In any event, whatever way you look at it, 2004 still holds the record for extent loss since 1st August, not 2008.

588. Chris
Posted Aug 14, 2008 at 3:03 AM | Permalink

Any chance of a Sea Ice Stretch Run #3 soon? This page seems to be growing like the open water in the Siberian seas :) Given issues to do with when freeze cycles start and anomalies level out (#570) the finer points of this debate could run and run for several months yet……

589. STAFFAN LINDSTROEM
Posted Aug 14, 2008 at 3:37 AM | Permalink

589…Chris, we must first come to #666, as the Devil
is in the details…Chris have you read “THE 3 POLYAKOVS”[pdf]
On the Siberian side, sea ice seems having been as thin as now
in the late 30’s and perhaps also mid fifties [strong positive NAO]
are 2 Alert stations…Check summer of 1995 et explique-moi..!!
I’ve downloaded the EC ice data, which goes back to 1948, often
weekly…so I’ll be back, baby … ice!

590. AndyW
Posted Aug 14, 2008 at 3:55 AM | Permalink

Thanks Chris for the correction, can I blame my spreadsheet Sum? Damn Microsoft! :)

I get 1.07Million for 2008 soI am not sure where I have gone wrong.

-102656
-104844
-87031
-67500
-116719
-145000
-94219
-625
-67344
-73750
-52343
-69063
-91719

= 1.07M

????
Regards
Puzzled of Sevenoaks

591. AndyW
Posted Aug 14, 2008 at 4:03 AM | Permalink

OK, worked out where I went wrong, my additions take into 31st July by adding the 1st to the mix of course as it is the day before. Still smaller than 2004 though which had a late season charge.

592. Aaron Wells
Posted Aug 14, 2008 at 9:02 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data.

Daily Arctic Sea Ice Extent Reduction Day 226

Arctic Sea Ice Extent Day 226

2008 Arctic Ice Extent Differences From Previous Years Day 226

Posted Aug 14, 2008 at 10:38 AM | Permalink

The annual hemispheric shift to NH climatic autumn is underway. Some regions started their climatic autumn 3 to 4 weeks ago. Of course, last year, a number of places in the NH began climatic autumn nearly as early, and yet, look what happened with the behavior of NH sea ice.

594. Posted Aug 14, 2008 at 10:41 AM | Permalink

Re #581
Thickness is dropping about twice as fast as area/extent, see here re. thickness

Re #583
DeWitt, another big drop in area today, now 4.00 (-0.10) to an anomaly of -1.73

595. DeWitt Payne
Posted Aug 14, 2008 at 10:57 AM | Permalink

Phil,

I noticed. Here’s the plot of smoothed area loss vs. smoothed average area loss for the same date. It’s pretty ugly. The loss rate for 2008 should be decreasing fairly rapidly by now. Instead it’s been nearly constant. Unless the loss rate returns to average real soon now, the 2007 minimum is not out of reach.

The Antarctic area is increasing rapidly.
area difference anomaly
14.441 0.242 0.202

The anomaly has increased from -0.99 to 0.202 in two days! That’s a 1% increase in area near the peak area. Maybe the 2007 record isn’t out of reach after all.

596. DeWitt Payne
Posted Aug 14, 2008 at 11:27 AM | Permalink

To put things in terms of the baby ice metaphor: Baby ice area is in the ER on life support. They haven’t called the priest yet to administer Last Rites, but someone is looking up the the priest’s phone number just in case.

597. DeWitt Payne
Posted Aug 14, 2008 at 11:30 AM | Permalink

Misread stupid calculator display. That’s a greater than 3% increase in area in two days.

598. Steve Geiger
Posted Aug 14, 2008 at 12:23 PM | Permalink

sort of OT, but came across this passage in a book I picked up this week:

“In recent years there are many signs to prove that the Arctic is slowly melting. This is shown by the rise of average temperatures, by the distribution of the pack ice, and by the recession of glaciers in Norway, Spitsbergen and Greenland. In northern Finland, the vegetation period is now from ten to fourteen days longer than it was twenty years ago. This is of tremendous importance in the Far North, where every hour of sunlight counts.”

And yes, of course the book was published in 1957 “All About the Artic and Antartic”. It would be interesting to see what, if anything the journals were saying about this at the time.

599. See - owe to Rich
Posted Aug 14, 2008 at 1:38 PM | Permalink

Regarding the overall progress of ice minima from 1979 to present, we should not be surprised, given the overall rise in global temperatures up until 2007, to see a negative trend. If global temperatures stay lower for a while, the delay before the response in which ice increases should be of some interest to measure the inherent lag. Of course, even if 2008 is low, if it turns out to be higher than 2007 we could argue that it has already responded. And then of course 2009 gets even more interesting, to confirm or deny that response.

Rich.

600. bender
Posted Aug 14, 2008 at 1:41 PM | Permalink

The loss rate for 2008 should be decreasing fairly rapidly by now. Instead it’s been nearly constant.

I fear your neglect of autocorrelation at short and long time scales may get the better of you!

601. DeWitt Payne
Posted Aug 14, 2008 at 1:48 PM | Permalink

I’ve come up with a crude projection of minimum area. I take current area divided by current extent and multiply by projected minimum extent. It’s crude for a variety of reasons. First, area is the product of extent times concentration. Both are functions of time and in the past it looks like concentration has reached its minimum weeks before minimum extent. Second, current concentration behavior with time is very different from past average. In the past, concentration would be reaching its minimum about now. Currently the concentration is decreasing, rapidly. That means the projected minimum is biased high. CT gives the long term area data along with the current area, but the extent average I have is only for 2003 to 2006, so my average concentration is extremely likely to be biased high. Anyway, here are the plots of interest:

Projected minimum Arctic ice area.

Ice concentration.

602. DeWitt Payne
Posted Aug 14, 2008 at 1:54 PM | Permalink

bender,

I fear your neglect of autocorrelation at short and long time scales may get the better of you!

I have no doubt about it. If I knew more statistics I might be able to do something about that, but I don’t. The data are all available if someone who knows more than I do wants to give it a shot. Either that or point me at a suitable resource. I think I’m done concentrating on the details of line-by-line models so I might actually have the time.

603. DeWitt Payne
Posted Aug 14, 2008 at 2:07 PM | Permalink

bender,

The average rate of change in area was about the same for the average and 2008 in early August. I’m not at all sure how autocorrelation would explain the current divergence. Besides, the plot is EWMA, if it wasn’t autocorrelated before smoothing, I think it certainly would be after smoothing.

604. DeWitt Payne
Posted Aug 14, 2008 at 2:07 PM | Permalink

Autocorrelated over the short term anyway.

605. DeWitt Payne
Posted Aug 14, 2008 at 2:38 PM | Permalink

Looking more closely at the average area curve on CT, I take back the statement about minimum concentration occurring earlier than minimum extent. It looks like on average minimum area and extent happen about the same time, mid-September. There was a period of rapid area loss starting in mid-August 2007 that made the area drop to near minimum a few weeks early.

606. TAC
Posted Aug 14, 2008 at 8:56 PM | Permalink

Preliminary Unofficial Day 227 Race Report
2008 has a moderate day, losing ground wrt 2005, widening the gap wrt 2006.
8 15 2002 6.375000 -0.086094
8 15 2003 6.677656 -0.064219
8 14 2004 6.753906 -0.068907
8 15 2005 6.183125 -0.068594
8 15 2006 6.363438 -0.040625
8 15 2007 5.307344 -0.040469
8 14 2008 6.077344 -0.054531

607. Real Richard Sharpe
Posted Aug 14, 2008 at 9:38 PM | Permalink

I find it strange that people make pronouncements based on un-restated results … Can we have comparisons based on the final results …

608. STAFFAN LINDSTROEM
Posted Aug 14, 2008 at 11:50 PM | Permalink

#608…TAC… …7344… Four last digits are the same…AS 2007

So make that number final …LOL [DITD…]

I have more numbers…From Alert Ellesmere Island
Ice thickness These numbers are available from
Environment Canada: Start 1961 end 2004 Some years
missing …NB Max thickness

1. 1996-06-05 ……240 cm
2. 1977-06-10 ……236 cm
3. 1972-05-12 ……235 cm
4. 1984-05-25 ……232 cm
5. 1964-06-05 ……231 cm
6. 1976-06-11 ……229 cm
7. 1963-06-07 ……226 cm
7. 1995-05-17 ……226 cm
9. 1994-06-09 ……219 cm
10. 1971-06-04 ……218 cm
11. 1966-06-17 ……217 cm
11. 1993-05-23 ……217 cm
13. 1970-06-20 ……213 cm
14. 2000-05-31 ……212 cm

And so the thin ones:

1. 1982-05-28 ……164 cm
2. 1987-05-29 ……170 cm
3. 1979-06-22 ……178 cm
4. 1973-06-22 ……180 cm
4. 1988-06-03 ……180 cm
4. 2003-05-28 ……180 cm
7. 1986-06-06 ……184 cm

Ellesmere Island and Alert are supposed to be in the “cool”
part of the rapidly warming Arctic. Annual variation is
great ie 1972 and 1973…More stations to come!

609. b
Posted Aug 15, 2008 at 12:32 AM | Permalink

west antarctic melt debunked!!!

Prevoius changes in temperature almost 3 times the current.

Quotes:
1) (supposed proof of global warming) Schneider and Steig estimate that West Antarctica warmed about 1.6 degrees F (0.9 degrees C) over the 20th century.

2) (natural changes much more that our current catastrophy) For example, during a major El Nino event from 1939 to 1942, temperatures in West Antarctica rose by about 6 to 10 degrees F (3-6 degrees C), and then dropped by an estimated 9 to 13 degrees F (5-7 degrees C) over the next two years.

610. Aaron Wells
Posted Aug 15, 2008 at 8:45 AM | Permalink

The final revision is in for yesterday’s data. Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data.

Daily Arctic Sea Ice Extent Reduction Day 227

Arctic Sea Ice Extent Day 227

2008 Arctic Ice Extent Differences From Previous Years Day 227

611. WhiteBeard
Posted Aug 15, 2008 at 11:40 AM | Permalink

# 611 b:

west antarctic melt debunked!!!

Well, that isn’t what I read from the post you link to. Do you have any understanding of the processes they’re reporting?

What I take away is that the West Antarctic Ice Sheet underwent 1.6 C degrees of climatic warming during the 20th Century. There is also a report of excursions, presumably the most extreme within that century, from that long term trend, which tie to oscillations in the planetary climate system.

Excuse me, I’m not a regular here, and I don’t know who to simply refrain from feeding and needlessly cluttering the thread.

To the creative writing contingent: A suggestion on the saga of the babies.

A treatment relating the annual resurrection being seeded by some Norse God spilling his last Highball as he stumbles home from the Autumnal Equinox Celebration. Perhaps Lindstroem can flesh this out crystallize the concept?

612. Gunnar
Posted Aug 15, 2008 at 12:12 PM | Permalink

May also have something to do with moving away from the pole. A sped up version of the same thing: a big iceberg drifts south. A temp measurement on the berg would record rising temperatures.

613. DaveM
Posted Aug 15, 2008 at 2:48 PM | Permalink

A pertinent story also posted at Watts.

http://www.theregister.co.uk/2008/08/15/goddard_arctic_ice_mystery/

614. STAFFAN LINDSTROEM
Posted Aug 15, 2008 at 7:48 PM | Permalink

#613 Whitebeard … back from my other flat in the outer suburb,
I can add to my post no 610 THIS : Phil. where art thou?
Eureka Nunavut Thickness of sea ice … begins well for Phil.
….1957-06-02 277 cm !! BUT Phil’s claim reduction 1997-2004
not here, still EUREKA: 1997-05-21 198 cm; 2004-05-21 251 cm …
HALL BEACH then: 1997-06-06 203 cm; 2004-05-07 190 cm; 2004-05-28 148 cm
[early melt or/and reduction that year but not in Hudson Bay!]
Going through the archipelago to the SE, IQALUIT [ex Frobisher Bay]
1997-05-09 153 cm; 2004-05-08 151 cm… To be contnued!!

615. TAC
Posted Aug 15, 2008 at 9:05 PM | Permalink

Preliminary Unofficial Day 228 Race Report
2008 has a big day, likely increasing its lead on 2005 and greatly increasing its lead on 2006.
8 16 2002 6.391094 0.016094
8 16 2003 6.640313 -0.037343
8 15 2004 6.692813 -0.061093
8 16 2005 6.100156 -0.082969
8 16 2006 6.339219 -0.024219
8 16 2007 5.241406 -0.065938
8 15 2008 5.986094 -0.085000

616. Mike Bryant
Posted Aug 15, 2008 at 9:28 PM | Permalink

Still closer to 2004 than 2007…

617. STAFFAN LINDSTROEM
Posted Aug 15, 2008 at 9:50 PM | Permalink

#617,618 TAC, Mike Bryant … The last week or so, we have’t
seen any any revisions, CMIIW, to the first preliminary or,
if you like “unofficial” numbers… Hence HARD QUESTION: How difficult can
it be for that program/me to count the pixels??????? And do it
correctly? I’m a novice here…Phil.?? [Or are you scared away
by my non-alarming sea ice thickness numbers?? TIAAMOM]

618. Posted Aug 15, 2008 at 9:51 PM | Permalink

Re #616

619. DeWitt Payne
Posted Aug 15, 2008 at 9:55 PM | Permalink

Projected extent is now 5.2 Mm2 +/- 0.5 on 9/14. 2005 and 2002 (barely) are the only years within reach. About thirty days left.

620. Real Richard Sharpe
Posted Aug 15, 2008 at 10:11 PM | Permalink

Re: 620.

So, by the look of page 16, their prediction is no Arctic ice at all sometime between 2012 and 2014.

Well, at least that is a prediction we can check.

621. STAFFAN LINDSTROEM
Posted Aug 16, 2008 at 2:38 AM | Permalink

#620 Phil. … What is your own take on this??
A report presented in Jan 2008 in Sapporo, Hokkaido,
Japan as part of “Sustainability week” [When I see or hear
the word “sustainability” I always get SUSPICIOUS…MORE THAN USUAL=ON]
And Phil. it was not that much to read because a few scary diagrams
are so more impressive…OK You cling to Maslowski and his group BUT there
are other scientists out there with somewhat different opinions:
One, certainly not known as a “contrarian” is our friend William
Connolley…Take a look at his blog and see what he has to say about
an ice-free Arctic in 2013! Environment movement at its worst always
warns of linear changes, reality seems to miss that almost always?!
PS. In that report they even BEG for more money for “dedicated computer
resources”… Are they afraid they wouldn’t get it?? DS.

622. Mike Bryant
Posted Aug 16, 2008 at 7:08 AM | Permalink

It is odd that there have been no revisions lately. Maybe today?

623. Mike Bryant
Posted Aug 16, 2008 at 7:11 AM | Permalink

Also the 85,000 flat, looks odd.

624. Posted Aug 16, 2008 at 9:27 AM | Permalink

Re #624

There are revisions everyday, perhaps TAC can’t be bothered to post such minor changes?

Today:
preliminary 8 15 2008 5.986094 -0.085000
revised 8 15 2008 5,983,125 -0.087969

625. Aaron Wells
Posted Aug 16, 2008 at 9:55 AM | Permalink

Phil is correct. There are normally revisions every day by 10:00 am East Coast US time. The only exception came one day this week when there was no revision. Maybe the guy who revises had the day off, or they decided that the difference wasn’t enough to update the data. I think the reason why it is not always posted here as much as it used to be is just that those who have been doing it may not have the time.

I always wait until after 10:00 am to make and post my graphs. I usually indicate that the revisions are in when I post them. I don’t always mention what the revision was.

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data.

Daily Arctic Sea Ice Extent Reduction Day 228

Arctic Sea Ice Extent Day 228

2008 Arctic Ice Extent Differences From Previous Years Day 228

Also, here is an extra graph that Phil will find gratifying. It tracks the Sea Ice Extent loss from each respective year’s maximum ice extent (drop from peak). The relevance of this graph is that 2008 had a high peak value during March. It appears that 2008 will pass 2007 soon, but may end up around the same value because 2007 is entering a period where it dips, but resumes a surge a little bit later. I hesitantly post this graph…. but I have to remain objective. ;-)

Arctic Sea Ice Total Drops from Peaks

626. See - owe to Rich
Posted Aug 16, 2008 at 10:54 AM | Permalink

Ice area on Cryosphere Today is continuing to drop rapidly. The anomaly only has to drop 200000 km^2 in 15 days to match the 2007 minimum.

But here’s something curious: when I looked at the 4 versions (old(ssmi), low, medium, high), I got very confused about the state of the North West passage, which appears to differ significantly in the 4 views. Why would that be?

Running the animation in the old version, it looks as if the NWP has actually iced up a bit more in the last 4-5 days.

Suggestions appreciated,
Rich.

627. Posted Aug 16, 2008 at 11:28 AM | Permalink

Re #628

Regarding the NWP the southern route was officially declared open a couple of days ago and yachts are sailing through it as we speak. Looking at Uni Bremen the northern route is clearing fairly quickly, wind shifts up there can blow ice out of the smaller straits into the main passage also I believe there was some night time surface ice too. The ice seems to be being blown to the south of the passage now:
Today’s image

628. STAFFAN LINDSTROEM
Posted Aug 16, 2008 at 12:33 PM | Permalink

#627 …Aaron…”…remain objective…” How old are you,
10??? Joking apart, you can be the “middle man” Between
the warm angel Phil. and me, the cool devil…[Staffan,
joking apart…Are you mental?? LOL…]
Talking of Phil. …
Your referred Maslowski et al report from 2008/01
As said before, not that much to read, but more how
to evaluate digrams:
On page 5, out of 18, there are 3 diagrams showing
arctic sea ice thickness: The first from 1994, first
third of april, a cruise and that is the Lincoln Sea
to the Beaufort Sea forth and back and up to NP or even
beyond, how many rounds in 10 days??
The second, same tour?? as 1994/04 a longer one,
SCICEX 1999-04-02 to 1999-05-13, more rounds?, but in
the high arctic, sea ice is most often still thickening..
The third is called “wide-basin”!! Have they now also
included russian measurements?? Who knows?
But this one is 2004-03-01 to 2004-03-29 [My comment: Why
so early was the ice disappearing already??]
Result : Arctic sea ice thickness POSSIBLY decreasing
twice as fast as sea ice extent/area…
ALARM CONCLUSION: “IF THIS TREND PERSISTS THE ARCTIC
OCEAN WILL BE ICE-FREE IN SUMMER IN AROUND 2013″
In summer means mid July until mid September here!?
My comment: Climatic summer temperatures will soon follow,
Go for the N Greenland beaches …Finally polar bears
in sun glasses reading the Guardian Monbiot …So
folks, we can have some “betting” on that! AS usual
no money of course, only personal prestige…
There is also a more scientist to scientist version
of this report which I’ve found… Only 9 pages
And questions about wind-induced low arctic sea ice
extent/area in 2007! Wasn’t in the “Sapporo version”
Google “McNamara sea ice 2006″ and you will find it!
So we have POLYAKOV et al on the Siberian side:
Laptev Sea and Chukchi Seas: DECREASING ice thickness,
BUT in the Kara and East Siberian Seas INCREASING thickness!!
[Chukchi and East Siberian Seas
diagrams are reversed as NOTED by me earlier…!]
These diagrams show 1940-2000ca development.
Let this cliffhang until tomorrow…

629. TAC
Posted Aug 16, 2008 at 12:57 PM | Permalink

Phil. (#626):

…perhaps TAC can’t be bothered to post such minor changes?

Yeah, I suppose I should post updates; on the other hand, laziness is a powerful motivator.
;-)

630. STAFFAN LINDSTROEM
Posted Aug 16, 2008 at 1:45 PM | Permalink

#629 …Oh no Phil. … Tiger is eating Baby Ice…
BTW Can you name the yacts that are sailing through
as we blog-speak…??[NORDREG CANADA Not compulsory, though]
The southern passage aka The
Amundsen passage, hmm. The Parry Channel is more
suitable for commercial traffic IF open…
STATEMENT: I love both TIGERS and BABY ICE!

631. Posted Aug 16, 2008 at 2:05 PM | Permalink

Re #632

Berrimilla
Tyhina
Amodino
Baloum Gwen
Southern Star

are the ones I know of, they’re all transiting the Larsen Strait I believe.

632. STAFFAN LINDSTROEM
Posted Aug 16, 2008 at 3:26 PM | Permalink

#633 Saturday, 16 August 2008
Ice free and Peel

Short call from Alex,

They have decided “to use Peel Sound over Bellot/Prince
Regent Inlet for a variety of reasons” to be discussed
someplace other than the expensive sat phone.
Alex gave his position in relation to some island. My tiny brain and poor reception lost it. I think he said “Bear Island” but I only see Barth Island which is consistent to the Berri’s speed. About half way up the west coast of Summerset Island.
Snowing, NW and cold about covers it.

Cold NW winds expected all the way up.
New ice still forming around Banks island to the west.
A little old ice expected at the top end of Peel…
nothing like they have been through.
The plan now is to get the hell out as fast as they can.
This type of cold chills to the bone and I considered
worse then -40. I used to wear my best winter gear to
stay warm.

Pat
Posted by Berrimilla DownUnderMars at 22:00

633. TAC
Posted Aug 16, 2008 at 9:05 PM | Permalink

Preliminary Unofficial Day 229 Race Report

2008 has another big day, increasing its lead on 2005 and 2006, and closing the gap a bit on 2007.
8 17 2002 6.348594 -0.042500
8 17 2003 6.633594 -0.006719
8 16 2004 6.611250 -0.081563
8 17 2005 6.044219 -0.055937
8 17 2006 6.303125 -0.036094
8 17 2007 5.194688 -0.046718
8 16 2008 5.910000 -0.073125

634. DeWitt Payne
Posted Aug 16, 2008 at 9:37 PM | Permalink

Projected 5.2 +/- 0.4 Mm2 on 9/15

The smoothed rate curve is tracking 2004 right now. If that continues to be the case, expect another week of extent loss at about the same rate. 2004 also had an earlier than average minimum extent date at 9/11.

635. Mike Bryant
Posted Aug 16, 2008 at 9:37 PM | Permalink

2008 closer to 2007 than to 2003.

636. mark in austin
Posted Aug 16, 2008 at 9:38 PM | Permalink

so, where can we get updates on how fast the Antarctica is growing? i noticed on cryosphere today that the graph is almost straight up and now it looks like it has a legit chance of surpassing last year’s record ice build up.

637. STAFFAN LINDSTROEM
Posted Aug 16, 2008 at 9:51 PM | Permalink

#634 “…The plan is to get hell out…”
Alert AP is far north of Berrimilla route, but:

ImageryCurrent Conditions

-8 °C
Date: 11:00 PM EDT Saturday 16 August 2008

Forecast not available for this location
Record ValuesHistorical WeatherHistorical Data
Yesterday Max: 0.0°C Min: -2.5°C Precip: 1.3 mm

Condition: Fog
Pressure: 99.8 kPa
Tendency: falling
Visibility: 2 km

Temperature: -7.6°C
Dewpoint: -8.0°C
Humidity: 97 %
Wind: W 11 km/h

[Good Old MOTHER WINTER IS BACK (AT LEAST FOR A WHILE)
KING BORE has had a sex change… Don’t you say
“all winters’ mother” etc. … ]
starts writing things like this…hell freezes in…LOL
Wind Chill: -13
Text ForecastAir QualityUV ForecastForecast

638. BarryW
Posted Aug 16, 2008 at 9:58 PM | Permalink

Re 636

The mean of the 2006 and 2007 minimums is ~5.018 so with your projection 2008 winds up right in the middle.

639. DeWitt Payne
Posted Aug 16, 2008 at 10:02 PM | Permalink

mark in austin,

I was going to post Antarctic results yesterday, but it got eaten by some sort of site problem and it wasn’t worth reconstruction.

Here’s the results for data posted at CT 8/16 for ice area for both poles:
region area difference anomaly
Arctic 3.89 -0.079 -1.800
Antarctic 14.838 0.153 0.515

That’s a gain of 0.837 Mm2 in 4 days. The anomaly is well into positive territory but the rate of increase will have to continue to be larger than average to reach record territory, i.e. greater than 1.

As far as the Arctic goes, 2007 seems to be within reach but it depends on a lot of variables. I don’t trust my empirical projection of 3.38 Mm2 because it’s dropping at a rate of -0.04/day. That only has to continue for ten days to have the projected value lower than 2007. OTOH, there’s less than 30 days left to probable minimum and the loss rate has to start decreasing soon.

640. Aaron Wells
Posted Aug 16, 2008 at 10:13 PM | Permalink

The smoothed rate curve is tracking 2004 right now.

I have been noticing the same thing with the raw rate curve. Here is the unsmoothed curves, showing ’08 tracking ’04 pretty closely.

Daily Sea Ice Reduction Rates ’08 vs ’04

If area reduction continues to track ’04, then we might be able to estimate the reduction from day 229 to minimum based upon the reduction from day 229 to minimum of year 2004, which by my calculations was a drop of 802,500 km^2 (day 263, to a minimum area of 5,808,750 km^2).

If we apply the same drop over that same period, then we can estimate a 2008 minimum of today’s amount (5,910,000) minus 802,500 km^2. That gives us a crude estimate of 5,107,500 km^2. That is not far off from DeWitt’s smoothed estimate of 5,200,000.

641. Aaron Wells
Posted Aug 16, 2008 at 10:32 PM | Permalink

I’m not sure if anyone has mentioned this web site before in this or the previous thread, but it is great for checking current weather/temperature conditions of various locations in the arctic circle:

Athropolis Map of the Arctic

Click on any of the little yellow circles, which indicate weather reporting stations, and get the current weather conditions.

For example, weather conditions for Alert, Nunavut, Canada from 30 minutes ago were:

Weather report as of 30 minutes ago (04:00 UTC):
The wind was blowing at a speed of 2.6 meters per second (5.8 miles per hour) from West in Alert, Canada. The temperature was -9 degrees Celsius (16 degrees Fahrenheit). Air pressure was 998 hPa (29.46 inHg). Relative humidity was 100.0%. There were a few clouds at a height of 30 meters (100 feet), a few clouds at a height of 2134 meters (7000 feet) and a few clouds at a height of 6096 meters (20000 feet). The visibility was 24.1 kilometers (15.0 miles).

Enjoy.

642. STAFFAN LINDSTROEM
Posted Aug 16, 2008 at 11:37 PM | Permalink

#634,636,639

DWP, in relation to Berrimilla [for all you lazy ones:
She’s a 33 feet yacht from down under-Sydney NSW Australia
aka “Aussieland”] and the Weather report from Alert AP,
there is evidently very thin night-old ice forming…
SO: Can the satellite ice detection system “see” that??
Phil.?? Every square cm is important here…Last year at
this time basically all of Parry Channel was open CMIIW,
Phil. And the Amundsen Passage [AMP? in contrast to NWP]
HAS been used in the 70’s by a little bigger yacht(s)
On YouTube there is a German boat in 2004. Did they make it
all throught without help of an icebreaker??

643. DeWitt Payne
Posted Aug 16, 2008 at 11:47 PM | Permalink

Phil,

The dire predictions in your link look like cherry picking the worst possible slope. I can do the same thing with the Arctic MSU temperature anomaly. If I plot the EWMA smoothed anomaly from 1/95 to 12/05 and calculated a linear trend, I get a slope of 0.82 degrees/decade. Project that to 12/2013 and the predicted temperature anomaly is 1.63 degrees. If that were to be the case, I would not be surprised to see a nearly or completely ice free Arctic ocean in September. The only problem with that is that the Arctic anomaly is not following that trend. Currently it’s 0.4 degrees below the linear trend, and its maximum value in 2006, and decreasing.

I’ve picked the values of the maximum area off the CT Arctic chart and calculated the average of the max and min. I’m using this to approximate the median area. Plotting this value vs the annual average NoPol anomaly and doing a linear regression gives this plot. The p value of the slope is 3E-08 and the 95% confidence limits are -0.073 to -0.043. So right now, the 2013 projection is not looking good. Unless the minimum area this year is less than 2.5 Mm2, the median area will be larger than 2007, in agreement with the lower average anomaly for the last 12 months.

644. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 2:35 AM | Permalink

#645 DWP, I assume you refer to the “Maslop…Maslowski” report
“…warns of linear changes, reality seems to miss that almost
always.”[my comment then] What Maslowski et al probably are right about is that Pacific
warm water advection is responsible for at least 60 % of the
thinning/melting/reduction of arctic ice. So we could have
substantial melting from below even with somewhat lower surface air
temperatures… But again, reality will probably catch up and turn the
currents around!?

645. Chris
Posted Aug 17, 2008 at 4:41 AM | Permalink

Looking at sea ice extent, summer 2008 still looks notable for the failure of the “baby ice” to disappear as predicted:
On June 1st 2008, the sea ice extent was 141,094 km2 greater than a year previously.
Now, as of August 16th 2008, after two and a half months of Arctic summer, the sea ice extent is 715,312 km2 greater than a year previously (despite the recent Siberian heatwaves)

Looking at sea ice area, the next couple of weeks will be interesting. The figure is currently about 900,000 km2 greater than the 2007 minimum. A pessimistic view says that if the area keeps up its recent rate of reduction, then the 2007 minimum could be matched. But an optimistic view says that the area may well bottom out in the next couple of days, just like it did a year ago (also after steep drops)

In this context it could be significant that the Siberian heatwaves may finally be starting to wane while the relatively cold conditions elsewhere in the Arctic look to be continuing http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/arcisoTTPPWW.gif

The dramatic increase in sea ice area around Antarctica in the past week (+1.111 million km2 from 9th-16th August, representing an anomaly change of -0.175 to +0.515 million km2 which dwarfs the Arctic anomaly change of -1.655 to -1.800) goes to show that just because ice area/extent has a particular trend one week doesn’t mean it will be the same the next.

In any event, even if 2008 ice area does approach the 2007 minimum, remember that the anomaly stayed close to a respectably normal -1 million km2 (balancing the consistent +1 million km2 in Antarctica for much of this year) until it started to drop substantially in August i.e. a month later than in 2007. If any substantial drops are delayed by a further month in 2009, they simply won’t happen!

646. Posted Aug 17, 2008 at 8:45 AM | Permalink

Re #645

I can do the same thing with the Arctic MSU temperature anomaly.

Any idea what ‘Arctic MSU temperature’ is, since MSU can’t measure above ~80ºN?

647. Chris
Posted Aug 17, 2008 at 8:57 AM | Permalink

The link I added earlier has been updated from 6 GMT to 12GMT today………and suddenly shows a massively deepened low i.e. storm over the Siberian seas. I’m not sure it was forecast to become so intense, and I wonder if the chart is exaggerating it (comparing other charts but I can’t find any so recent…)
At least it’s not dragging much warm air up from the continent this time – in fact quite the reverse, as there’s now a lot of cold and snowy polar air wrapped around it, following the recent lurch into winter over the north pole which is starting to spread………. I’d say the next few days are quite unpredictable in terms of ice area and extent, but beyond that the 2008 “baby water” is looking increasingly threatened :)

648. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 9:18 AM | Permalink

#649 Chris, the Germans do anything to be sexy
on Sundays, Lidl is only closed in Germany that
day and…LOL… Seriously another German site:

http://www.wetterzentrale.de/pics/bracka.html

It’s really from UK Met Office, the 963 MB or so
Blizzard [still my neighbour’s name!!] in the
high Arctic should be some 974 MB 500 KM W IRELAND,
Otherwise, ICEAGE HAS JUST BEGUN…

649. AndyW
Posted Aug 17, 2008 at 9:49 AM | Permalink

No, I think the prediction was changed when they got later measurements showing that the young ice was thicker than they thought in July, so then they said it would melt later but of course that would be well past the peak season so fighting a losing battle. I think they shape of Aarons melt grphs does show that the thinner ice of this year is melting more in this period well past peak. 2007 had well and trully shot it’s huge bolt by this time last year where as 2008 is a steady trudger. It still won’t get anywhere near though. 2004 is now the interesting year to compare with,2008 always did look most like it from geographical location of melt and it seems to be following it in the figures too now.

As for that joker at The Register, thanks but no thanks, they can’t even get computer hardware news right half the time ( their supposed area of excellence) so I am not taking that guy seriously at all. He just has an axe to grind. Pah.

650. Chris
Posted Aug 17, 2008 at 9:49 AM | Permalink

#650 lol!

Staffan, you might like the following links for Chelyuskin – I don’t think you’ll find a weather station further north on the Russian mainland?

See here for its location, and trends for next 7 days (temperature gradual fall from ~5C to ~0C, cloud cover mostly close to 100%..) http://www.fallingrain.com/world/RS/74/Chelyuskin.html
… And here for more an extended forecast: http://www.weather.com/outlook/travel/businesstraveler/extended/RSXX1594 (i.e. freezing conditions into next week) The game is up, the fightback is imminent, and first impressions suggest winter 08/09 is looking distinctly icy……..

651. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 10:03 AM | Permalink

#649,650 Chris, Myself… The BLIZZARD seems to be
in Nunavut, NWP Check the “Berrimilla” site [I wonder
if Berrimilla is Sydneyan for “Barry Miller??]
Resolute now [10:00 AM CDT] -0.9C, whereas ALERT +0.8C
NOW [11:00 AM EDT] THIS morning’s tmin was a staggering
-8.7C…The weather in the Nunavut archipelago is not
covered very well as the towns/villages are so far from
each other…

652. Chris
Posted Aug 17, 2008 at 10:05 AM | Permalink

Latest on ice area from CT:

Arctic 3.83 (-0.06) Anomaly -1.805 (-0.005)
Antarctic 14.944 (+0.106) Anomaly +0.612 (+0.097)

So Arctic melt has slowed down to normal pace; on the other hand, Antarctic freeze is already ~ 1 million km2 ahead of this day last year, and for those of you who like to extrapolate trends, growing at a rate to smash last year’s record to smithereens.

653. Chris
Posted Aug 17, 2008 at 10:15 AM | Permalink

#653 Yes I know, I’d already clocked the blizzards in Resolute – here’s another link if you’re into minus temperatures in favourite baby ice annihilation zones http://www.weatheronline.co.uk/Nunavut/Resolute.htm
Looks to me like there’s a lot of blizzards going on at the moment, and a lot more to come. Meanwhile, insolation seems to be becoming an increasing irrelevance as the month goes on (I’m sure that sunny spell on Wed in the Resolute forecast will melt a lot of ice :) )

654. Chris
Posted Aug 17, 2008 at 10:34 AM | Permalink

Meanwhile, back to a past speculation of mine…….. the recent surge in Antarctic ice growth has coincided with the highest daily SOI number in over 2 months, and the 5th highest since the height of La Nina in February, I make it. Now it was only one day, and at the moment the equatorial water immediately west of S America has an anomalously warm patch (+3.5C compared with ~ -2C a year ago). But the experts have increasingly ruled out an El Nino in the last couple of weeks because the tropical/south Pacific is generally just not warm enough. So is it yet possible that 2008 could follow 2007 with a La Nina to produce a repeat performance of the 99/00 back-to-back La Nina event, except this time as part of a downward temperature trend (as compared with the “bounce” from the 1998 El Nino, which turned out in retrospect to be part of a warming trend to ~2004) ?
It’s just a speculation, no more…

(here’s the link to daily SOI numbers going back to 1991: http://www.longpaddock.qld.gov.au/SeasonalClimateOutlook/SouthernOscillationIndex/SOIDataFiles/DailySOI1887-1989Base.txt )

655. Posted Aug 17, 2008 at 10:44 AM | Permalink

Phil, I restate my question:

Phil #528,

changing the energy balance/distribution of the atmosphere

and what changes in the distribution of energy are some well mixed GHGs causing?

656. DeWitt Payne
Posted Aug 17, 2008 at 10:56 AM | Permalink

Phil,

Any idea what ‘Arctic MSU temperature’ is, since MSU can’t measure above ~80ºN?

Nitpicking. The Arctic is defined as latitudes higher than 66.56083 degrees N (the Arctic Circle), not 80 N.

Noun
1. Arctic – the regions to the north of the Arctic Circle centered on the North Pole

So 60 to 82.5 should be a reasonable approximation of the Arctic.

657. kim
Posted Aug 17, 2008 at 10:59 AM | Permalink

Joe Romm, who edits dissent out of his own blog, is picking a fight with Andy Revkin at DotEarth over his tone in a recent column about icebreakers. They are arguing over how the Arctic melt is being portrayed. Andy argues from a much more sophisticated conception of the local and global factors at work up there.
============================================

658. Aaron Wells
Posted Aug 17, 2008 at 11:35 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data.

Daily Arctic Sea Ice Extent Reduction Day 229

Arctic Sea Ice Extent Day 229

2008 Arctic Ice Extent Differences From Previous Years Day 229

Arctic Sea Ice Total Drops from Peaks Day 229

659. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 11:46 AM | Permalink

#652 Chris, Chelyuskin is far north but the got a spoon or
two from the heatwave in E Europe, Volgograd 37C ca today
for example…Though it seems as heat bubbles/Hadley cells
are squeezed out of the system, this summer heatwaves
from Africa has come as broadsides, fairly extensive in
the beginning, but not as intensive as last summer’s “welding”
attacks on E Italy, Greece and quite limited parts of Balkan
This is hopelessly OT in a Arctic sea ice thread…but
it almost looks like Antarctic sea ice is targeting the “Kiwis”…
Oh good old AGW …

660. See - owe to Rich
Posted Aug 17, 2008 at 11:47 AM | Permalink

Re #628 and #629

So I’ll repeat it, with links; why does the high res picture look so different from the old style picture along the NWP? The latter’s NWP looks much icier. Is it something to do with the resolution?

Rich.

661. Posted Aug 17, 2008 at 11:51 AM | Permalink

Re #658

Any idea what ‘Arctic MSU temperature’ is, since MSU can’t measure above ~80ºN?

Nitpicking. The Arctic is defined as latitudes higher than 66.56083 degrees N (the Arctic Circle), not 80 N.

Noun
1. Arctic – the regions to the north of the Arctic Circle centered on the North Pole

So 60 to 82.5 should be a reasonable approximation of the Arctic.

Not nitpicking, I was asking what the quantity you referred to was, a bit of a stretch to call it NoPol though!

662. Chris
Posted Aug 17, 2008 at 11:52 AM | Permalink

Thanks for the graphs Aaron….

#650 Staffan maybe you’re right, the Germans were having a laugh after all: here’s the latest update from the chart I usually rely on for more detail http://www.weatheroffice.gc.ca/data/analysis/935_100.gif
Confirms the pattern of freezing temperatures over much of the Arctic, with milder air continuing to encroach from western Siberia but not as strongly as before.

663. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 11:57 AM | Permalink

#659 …THE RACE FOR 666… kim, Joe Romm seems to be a really
balanced guy, being somewhat of a warmista, or did I miss
something there eyeballing for 16.66 seconds …
[didn’t I tell you before? Andy is too soft…]

664. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 11:59 AM | Permalink

665 yes

665. Chris
Posted Aug 17, 2008 at 12:03 PM | Permalink

#662 “See – owe to Rich” – check out #557, #558, #653, #655 (and link in #664). In other words, it’s been *^\$&#~% cold in that part of Canada!!! (and set to continue that way http://wxmaps.org/pix/temp2.html )
The main reductions in ice extent/area in the last few days have been elsewhere i.e. the Siberian seas.

666. Jon
Posted Aug 17, 2008 at 12:05 PM | Permalink

So I’ll repeat it, with links; why does the high res picture look so different from the old style picture along the NWP? The latter’s NWP looks much icier. Is it something to do with the resolution?

They show the same thing. If you have a region with 20% in one, and then divide it into parts: one might be 40% and the other 0%. This is normal.

667. Kenneth Fritsch
Posted Aug 17, 2008 at 12:09 PM | Permalink

I don’t want the active posters to get me wrong here, as I respect the exchange of knowledge on this thread, but I cannot help commenting that this thread reminds me of watching an NBA basketball game on TV where one can lose interest until the final minutes of the game decides the outcome – unless, of course, there is a color commentator with the imagination and delivery of a jeez.

668. Posted Aug 17, 2008 at 12:20 PM | Permalink

Re #662

So I’ll repeat it, with links; why does the high res picture look so different from the old style picture along the NWP? The latter’s NWP looks much icier. Is it something to do with the resolution?

I mainly look at the hi res and Uni Bremen maps so I’m not too familiar with the other CT ones.
The new one has a non-linear color palette whereas the old ones are linear, also I’ve noticed that the old ones are indicated as ‘old(ssmi)’ which is the imager that CT has used in the past. It’s possible that the high resolution image that CT started using recently is based on the AMSR-E imager (the same as JAXA and Uni-Bremen). Regarding the NWP the low res is likely to have an effect because of the close confines on the archipelago. HTH

669. John Lang
Posted Aug 17, 2008 at 12:21 PM | Permalink

Another hires map showing ice concentrations is from NCEP at this link. (Updated each day.)

http://polar.ncep.noaa.gov/seaice/hires/global.xml

The comments about the Northwest Passage are relevant since this map shows there are no routes currently where you would have less the 50% ice coverage – mostly higher. Yachts can get through at this kind of ice coverage but it would be dangerous.

670. Posted Aug 17, 2008 at 12:33 PM | Permalink

Re #667

The main reductions in ice extent/area in the last few days have been elsewhere i.e. the Siberian seas.

Yes because that’s where the ice hadn’t melted as much earlier and which constituted most of the lag from last year. There’s no ice in the Beaufort Sea left to melt!
This situation has been apparent for some time, here for example.

671. Posted Aug 17, 2008 at 12:48 PM | Permalink

Re #671

I don’t buy that site, it doesn’t agree with the detailed Canadian ice maps nor the experience of the yachts sailing through that area over the last few days, basically mostly 1/10 except the ‘tongue’ being blown in from the NW.

672. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 1:02 PM | Permalink

#664 Chris .. That map unenlarged looked like … then I got
Hilarious Atmospheric Northern All Latitudes or WHAT??
From my dear Hokkaido over the Pacific to the Caribbean
with TS “Fay” just outside
Santiago de Cuba over the Atlantic and then N Siberia

#669 Monsieur Fritsch, NON et OUI…[this is a blog,
human exchange of views, opinions and prejudices…Sorry
Kenneth I’m perhaps younger than you so I shouldn’t really…]
We all miss the almost daily? stories of Baby Ice…
Phil. .. Why showing a tiger?? As we didn’t know we’re all
paper tigers…pining for the fiords… MR LINDSTROM IS or
was, kim, the captain of USGC Healy, the research icebreaker,
that is Ted Lindstrom…[YOUTUBE] If you are interested in
arctic sea ice and icebreakers check the tube; ODEN, YAMAL,
KIGORIA, HEALY ETC.[I WILL read Revkin on icebreakers]

673. Posted Aug 17, 2008 at 1:06 PM | Permalink

Re #657

Phil, I restate my question:
Phil #528,
changing the energy balance/distribution of the atmosphere

and what changes in the distribution of energy are some well mixed GHGs causing?

Increased energy in the troposphere & reduced energy in the upper stratosphere.

674. Chris
Posted Aug 17, 2008 at 1:26 PM | Permalink

#672 Sure, the small Beaufort Sea area as defined by CT melted some time ago, but if it had been warm enough the ice margin should have continued retreating into the Arctic basin, which it has hardly done at all this month http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=01&fy=2008&sm=08&sd=16&sy=2008 Of course CT also subsumes a large part of what I call the Siberian seas (for ease of reference) into the Arctic Basin area. So maybe I should phrase it in terms of quadrants in the link above, that is to say, the top-right quadrant has seen much greater melt due to relatively higher temperature anomalies. All I was trying to point out before was that just because there’s been high melt overall recently, doesn’t mean it’s surprising if melt has been much slower in the Canadian Archipelago.

675. STAFFAN LINDSTROEM
Posted Aug 17, 2008 at 1:26 PM | Permalink

#673 Phil. prepare for a severe chock…I’m inclined
Of course it could be correct in AMP and NWP areas,
but still have ice around S Ireland and the Baltic [have another
the Rocket scientist…No! The Aussie boxer…] But
you get sceptic even if you already are one…

676. MrPete
Posted Aug 17, 2008 at 1:38 PM | Permalink

For what little it is worth, last night was cold enough that several thousand feet at the top of Pikes Peak (and neighboring Almagre) were blanketed with snow.

August is normally when the last vestiges of the previous winter snow melt away even from north-facing crevices. Last year I was hiking Almagre in August, and did my last trip up in October just before first snowfall. I’m sure this early snow is not unique; it is unusual.

677. Posted Aug 17, 2008 at 1:49 PM | Permalink

Phil, #675:

Increased energy in the troposphere & reduced energy in the upper stratosphere.

And when did that reduction in stratospheric energy occur?
And what have you observed about those energy changes that, I quote, “must effect to some extent the winds and currents at the surface“?

678. Kenneth Fritsch
Posted Aug 17, 2008 at 2:28 PM | Permalink

#669 Monsieur Fritsch, NON et OUI…[this is a blog,human exchange of views, opinions and prejudices…Sorry Kenneth I’m perhaps younger than you so I shouldn’t really…]

We all miss the almost daily? stories of Baby Ice…

Staffan: Everybody is younger than I, so do not hold back with a yes and no. I also have come to enjoy your clipped but nuanced comments on this thread and others that sometimes appear to come by way of a translating machine, albeit a machine with character and sense of humour.

I also liked David Smith’s attempt on this thread to provide a simple ice extent/area/volume predictor using the early season albedo.

Also I do not think that jeez can just leave the baby ices hanging in limbo. We need closure – be it with a happy or sad ending.

679. crosspatch
Posted Aug 17, 2008 at 3:42 PM | Permalink

I would guess that melt ponds in the area around the pole are going to start freezing back up. It has been below -1C for at least 48 hours now. Camera 1 is reporting -2C and camera 3 with a newer shot shows ice on the bubble window. It looks like it might be the end of the melt season for the area around the pole itself.

680. David Smith
Posted Aug 17, 2008 at 4:31 PM | Permalink

Interestingly, the ice on which the “North Pole Webcam” is located has drifted southward. It is currently at 83N, northeast of Greenland.

Webcam location and data

681. Stefan
Posted Aug 17, 2008 at 4:56 PM | Permalink

What odds for North Pole kayaker Lewis Pugh http://polardefenseproject.org/blog/ to reach his objective?

682. Posted Aug 17, 2008 at 5:30 PM | Permalink

Re #682

Interestingly, the ice on which the “North Pole Webcam” is located has drifted southward. It is currently at 83N, northeast of Greenland.

And got ~0.5m thinner over the last month.

683. Posted Aug 17, 2008 at 5:57 PM | Permalink

Re #683

What odds for North Pole kayaker Lewis Pugh http://polardefenseproject.org/blog/ to reach his objective?

Given the route choice I would think not good.

684. TAC
Posted Aug 17, 2008 at 8:53 PM | Permalink

Preliminary Unofficial Day 230 Race Report
2008 has another 70K+ day, now 670K behind 2007.
8 18 2002 6.281406 -0.067188
8 18 2003 6.617656 -0.015938
8 17 2004 6.536094 -0.075156
8 18 2005 6.023594 -0.020625
8 18 2006 6.238594 -0.064531
8 18 2007 5.166250 -0.028438
8 17 2008 5.839531 -0.070157

685. AndyW
Posted Aug 18, 2008 at 1:26 AM | Permalink

I prefer the quickscat ocean masked and Danish site

used in conjunction.

Another day for 2007 outstripping 2006 and 2005. Somebody has to tell it needs a downward trend soon. Perhaps this next week will finally sdee it lose impetus.

686. Aaron Wells
Posted Aug 18, 2008 at 8:33 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. There was an ever-so-slight upward revision of the extent area this morning (~1400 km^2) (Some baby-ice survived which were first thought dead.)

Daily Arctic Sea Ice Extent Reduction Day 230

Arctic Sea Ice Extent Day 230

2008 Arctic Ice Extent Differences From Previous Years Day 230

Arctic Sea Ice Total Drops from Peaks Day 230

687. M. Jeff
Posted Aug 18, 2008 at 10:22 AM | Permalink

2008 Arctic Ice Extent Differences From Previous Years Day 230 links to “Arctic Sea Ice Extent Day 230″

688. Aaron Wells
Posted Aug 18, 2008 at 10:51 AM | Permalink

2008 Arctic Ice Extent Differences From Previous Years Day 230 links to “Arctic Sea Ice Extent Day 230″

Indeed it is. My bad. I’m not sure how that happened. Try this one:

2008 Arctic Ice Extent Differences From Previous Years Day 230

689. DeWitt Payne
Posted Aug 18, 2008 at 11:51 AM | Permalink

Ice Area
region area difference anomaly
Arctic 3.773 -0.057 -1.824
Antarctic 14.858 -0.086 0.472

The Arctic is still about 0.4 Mm2 ahead of 2007 but 2007 hit near its minimum early and then almost stopped losing or gaining for nearly a month. There is still a chance that 2008 will match or exceed 2007 for minimum area. In terms of true average area for the year, however, it’s not just the minimum, but also how long it stays near the minimum.

Even with the loss of area today, the Antarctic is still nearly 1 Mm2 ahead of 2007 with up to a month of freezing left.

Arctic extent rate is still tracking 2004 and losing extent faster than the recent average. Projected minimum continues to decrease and is now at 5.1 Mm2 +/- 0.4 on about 9/15. 2008 is now odds on to be second lowest extent since 2002.

690. Gerald Machnee
Posted Aug 18, 2008 at 12:28 PM | Permalink

There is some panic in the land. See:

http://www.theregister.co.uk/2008/08/15/goddard_arctic_ice_mystery/

691. See - owe to Rich
Posted Aug 18, 2008 at 2:08 PM | Permalink

What odds for North Pole kayaker Lewis Pugh http://polardefenseproject.org/blog/ to reach his objective?

(Phil): Given the route choice I would think not good.

I followed just one link from the first link, and didn’t get to the North Pole nor to the description of the proposed route to the North Pole. Still, I’ll take Phil at his word.

Another day for 2007 outstripping 2006 and 2005. Somebody has to tell it needs a downward trend soon.

Perhaps this remark reflects the difference between a sceptic and an auditor. A sceptic wants the ice to stop melting to help disprove AGW (or its amount). An auditor wants the ice to melt as much as it likes providing it doesn’t tell lies, in other words she wants it to tell a true tale of global warming or cooling. Given the apparent global temperature rise to 2002, followed by flat temperatures to early 2007, followed by a downturn, the lag in the system might mean we should expect to see continuing low ice levels. If 2008 happened to catch 2007 on ice area, it would not prove that global cooling has not been happening for 18 months.

The big deal is whether an ice free Arctic comes to pass by 2013, which I very very much doubt. (I suppose by that statement I am saying the lag should not be as much as 7 years.)

Rich.

692. Posted Aug 18, 2008 at 3:43 PM | Permalink

Re #693

What odds for North Pole kayaker Lewis Pugh http://polardefenseproject.org/blog/ to reach his objective?

(Phil): Given the route choice I would think not good.

I followed just one link from the first link, and didn’t get to the North Pole nor to the description of the proposed route to the North Pole. Still, I’ll take Phil at his word.

Very wise. ;)

From the web site: “On the 27th of August Lewis Gordon Pugh will attempt to become the first person to kayak to the North Pole. The 1,200km journey, across some of the most dangerous seas in the world, is scheduled to depart from the Norwegian island of Spitsbergen.”

693. bender
Posted Aug 18, 2008 at 3:45 PM | Permalink

#693

flat temperatures to early 2007

Someone may want to contest that assertion (which is true for the globe) with data specifically from the Arctic region.

694. Posted Aug 18, 2008 at 4:41 PM | Permalink

Re #695

#693
flat temperatures to early 2007
Someone may want to contest that assertion (which is true for the globe) with data specifically from the Arctic region.

I do this all the time!

Some data which shows that the ‘holarctic’ is behaving differently than the globe is shown below

This is only one month’s data but once in this site you can scan back and forth:

http://www.remss.com/msu/msu_data_monthly.html?channel=tlt

695. DeWitt Payne
Posted Aug 18, 2008 at 4:51 PM | Permalink

The Arctic temperature hasn’t been at all flat. It increased rapidly, 0.8 degrees/decade, from 1993 until about 2005 but since then appears to have peaked and begun to decline.

696. bender
Posted Aug 18, 2008 at 4:52 PM | Permalink

#696 Phil, Thanks. Any time-series data handy?

697. markinaustin
Posted Aug 18, 2008 at 8:26 PM | Permalink

interesting study that predicts 60 to 80 years of cooling ahead

http://www.milenio.com/mexico/milenio/nota.asp?id=651680

698. hswiseman
Posted Aug 18, 2008 at 8:51 PM | Permalink

Another down day for the Baby Ice. Oh, the humanity….

699. Aaron Wells
Posted Aug 18, 2008 at 9:43 PM | Permalink

Another down day for the Baby Ice. Oh, the humanity….

Where are you getting your information? JAXA? I have been checking them for the last 30 minutes and they are delayed in reporting.

700. DeWitt Payne
Posted Aug 18, 2008 at 10:22 PM | Permalink

Looking at the August 18 picture on the JAXA site, there’s a huge swath of data missing. I’m betting we won’t see a number for August 18 extent and will have to interpolate from the August 19 data, assuming it doesn’t have a glitch too.

701. Aaron Wells
Posted Aug 18, 2008 at 10:34 PM | Permalink

Looking at the August 18 picture on the JAXA site, there’s a huge swath of data missing. I’m betting we won’t see a number for August 18 extent and will have to interpolate from the August 19 data, assuming it doesn’t have a glitch too.

Yes. I noticed that too. I suspect you are right. It doesn’t look like they are going to post any data tonight.

702. STAFFAN LINDSTROEM
Posted Aug 19, 2008 at 12:09 AM | Permalink

#686 … TAC I haven’t seen the huge UPdate on Aug 17 2008
5840938 SQ KMS … Not much for us addicts, BUT it’s [1407]
65 sq kms bigger than Sweden’s smallest province (island of)
Öland (lit. Island-land) in the Baltic… It’s big enough
for my “datja”, and the royal family’s castle ‘Solliden’
just south of the island’s only city, Borgholm…, etc, etc
#699 markinaustin … He thinks the new LIA will be here
in 2 years if my was-always-too-lazy-to-learn-Spanish-knowing-
French-quite-well-Spanish serves me right…[Eso es el sol, stupidos!
…]

703. AndyW
Posted Aug 19, 2008 at 1:37 AM | Permalink

JAXA have posted a 67000 for 18th before correction so another big day for 2008 for this time of year. 2007 still has 3 big days though before having a cold snap around the start of September.

704. Hans Erren
Posted Aug 19, 2008 at 3:23 AM | Permalink

THe explosive eruption of Aleutian volcano Kasatochi on August7 (plume reached 35000 ft) might have a knock on effect on sea ice development.

705. TAC
Posted Aug 19, 2008 at 3:35 AM | Permalink

Preliminary Unofficial Day 231 Race Report
2008 has another big day, now 655K behind 2007.
8 19 2002 6.230156 -0.051250
8 19 2003 6.572656 -0.045000
8 18 2004 6.470156 -0.065938
8 19 2005 5.980469 -0.043125
8 19 2006 6.185156 -0.053438
8 19 2007 5.121563 -0.044687
8 18 2008 5.773906 -0.067032

706. STAFFAN LINDSTROEM
Posted Aug 19, 2008 at 3:35 AM | Permalink

…From the “Berrimilla” blog 2008-08-18 23:57 :

There are two rounds of
One for the Northwest Passage now and the other we will
(via UK).

The Berrimilla is the first boat to complete
the NW passage in 2008, beating the Amodino
by one day. (YAAA!!!) (I guess the Amodino
got out of the ice OK back in Peel)

I believe the Berrimilla is the first
Australian boat to complete the NW Passage!
(YAAAAA!!! CHEERS! homemade Coopers in the

I believe the Berrimilla is the only boat
to circumnavagate the world by the Horn
and sail the NW passage. (YAAA!! CHEERS!
Guinness if you ran out of Coopers)

Congratulations to Alex, Corry, and Kimbra!!

Not too much coopers please as there is
still a long way home.

Pat

707. AndyW
Posted Aug 19, 2008 at 6:34 AM | Permalink

The NW direct passage should be open this year soon. The NE passage looks like a none starter though.

708. Schnoerkelman
Posted Aug 19, 2008 at 7:58 AM | Permalink

#706 and my #503
Might want to have a look at this over at Wattsupwiththat.

Some of the comments there are amusing as well.

709. Mike C
Posted Aug 19, 2008 at 8:40 AM | Permalink

#709, doubtful, the temp at Resolute has been -2C for a few days and is snowing there. No NW direct this year.

710. Aaron Wells
Posted Aug 19, 2008 at 9:09 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. There was a larger-than-normal downward revision of the extent area this morning (~10,000 km^2).

Daily Arctic Sea Ice Extent Reduction Day 231

Arctic Sea Ice Extent Day 231

2008 Arctic Ice Extent Differences From Previous Years Day 231

I caught a formula error the drop-from-peak data in my spreadsheet which which was resulting in the subtraction from peak extent to not always be getting the peak row in the spreadsheet. I have corrected that now, and this graph is correct. The result is that 2008 has not yet eclipsed 2007 in the drop from the peak extents, although it is very close to crossing the 2007 line soon.

Arctic Sea Ice Total Drops from Peaks Day 231

711. Chris
Posted Aug 19, 2008 at 10:19 AM | Permalink

Looks like the heatwaves/warm southerlies in far northern Siberia are finally, finally going to come to a proper end on Friday. The heatwaves have been more persistent than any in the last decade, from what I can tell from the records at Tiksi (Laptev coast) anyway. My previous optimism (re: 2008 keeping up with 2006/2005) was based on the gamble that it would be just too unlucky for the thin ice in that region if such a thing kept happening. Well it has, and I was wrong :(
In the meantime, the warmth continues to eat a massive chunk out of the ice in that area, just like it did in the Beaufort sea last month (-0.12 today on CT)

712. DeWitt Payne
Posted Aug 19, 2008 at 10:31 AM | Permalink

CT ice area
region area difference anomaly
Arctic 3.653 -0.12 -1.916
Antarctic 14.779 -0.079 0.333

Baby ice area vitals continue to drop.

Arctic extent rate still on the 2004 path. A break on Friday would be right on schedule. Expect the Arctic area anomaly to continue to drop rapidly until then, though. Less than -2 is highly likely.

713. Chris
Posted Aug 19, 2008 at 11:16 AM | Permalink

Thanks DeWitt.

Just thought I’d put some figures on what I was saying about the Laptev heatwaves.
Bearing in mind that Tiksi is at 71 degrees north…..

I calculate that from Aug 1st-18th, the average maximum was ~17C, compared with ~13C in 2007 and under 10C in 2006. (The average minimum was over 9C i.e. comparable to the 2006 average max! and the sunshine looks to have been ~50% above average)

The forecast is for a maximum of 19C both tomorrow and Thursday. Then finally the maximum drops: Fri 9C, Sat 7C, Sun 3C, Mon 7C. And this time I’m certain it’s for real (a couple of weeks ago the 5-day forecast predicted a drop of at least 5C which simply failed to materialise, but we’re talking a drop of 10-15C this time, which is a lot to be wrong!)

Of course, heatwaves could take over elsewhere, and/or the low associated with the change could have adverse effects on the ice. But overall I would have thought a cooling in the area will do little harm to the ice, what’s left of it anyway…. Whether it’s in time to prevent 2008 getting perilously close to 2007’s area/extent records is another matter…… (As is whether the heatwaves can be used as an excuse against the argument that the 2nd year in a row of “unprecedented” summer melt is further evidence of AGW……)

714. AndyW
Posted Aug 19, 2008 at 11:30 AM | Permalink

#711 Mike C

The SST’s look pretty warm though

It’s still 1 month to go till the normal minima and 2008 has not been the normal late season melt so I am pretty confident it will be clear. We shall see though, it might take a sudden change for the worse/better ( depending on your viewpoint)

715. Posted Aug 19, 2008 at 11:46 AM | Permalink

Re #714

Arctic extent rate still on the 2004 path. A break on Friday would be right on schedule. Expect the Arctic area anomaly to continue to drop rapidly until then, though. Less than -2 is highly likely.

Also in 2007 the ice stopped melting by about the 20th and the area stayed flat for about a month, if this year’s ice keeps melting it could pass 2007 by the end of the month. Still lot’s of vulnerable fragmented ice out there, the ice last year at this time was more compacted which probably explains why it stopped melting? Current average concentration ~65% whereas it didn’t get below 70% last year.

716. crosspatch
Posted Aug 19, 2008 at 12:49 PM | Permalink

The “pole” cam (which is obviously drifting from the pole) is down to -4.5C today so that melt pond that was nearby should be freezing over quite a but by now. The cam lens is ice covered and the camera 3 shot shows considerable ice buildup in the mast visible on the right side of the picture. At -4.5C I would also expect to see sea ice begin to re-form.

717. bender
Posted Aug 19, 2008 at 1:02 PM | Permalink

#712

My previous optimism (re: 2008 keeping up with 2006/2005) …

You mean “pessimism”, right? We DON’T want this melt to happen, right? ;)

was based on the gamble …

Imagine. An alarmist willing to “gamble” using other people’s money.

Just sayin’.

718. Aaron Wells
Posted Aug 19, 2008 at 1:16 PM | Permalink

#712

My previous optimism (re: 2008 keeping up with 2006/2005) …

You mean “pessimism”, right? We DON’T want this melt to happen, right? ;)

Bender, the way I interpreted Chris’s comment was that “keeping up with 2006/2005″ meant keeping up with their extent area, thus meaning “not melting”. Thus optimism.

719. Aaron Wells
Posted Aug 19, 2008 at 1:20 PM | Permalink

In my above post, the quote:

You mean “pessimism”, right? We DON’T want this melt to happen, right? ;)

should have also been in a block quote.

720. Posted Aug 19, 2008 at 1:56 PM | Permalink

Re #718

The “pole” cam (which is obviously drifting from the pole) is down to -4.5C today so that melt pond that was nearby should be freezing over quite a but by now. The cam lens is ice covered and the camera 3 shot shows considerable ice buildup in the mast visible on the right side of the picture. At -4.5C I would also expect to see sea ice begin to re-form.

But the melt that counts is occurring below, that particular piece of ice has got ~0.5m thinner over the last month (down to 1.4 m).

721. BarryW
Posted Aug 19, 2008 at 2:01 PM | Permalink

Looks like there was a significant revision:

231 2008-08-18 5.763594 -0.077344

from

8 18 2008 5.773906 -0.067032

722. Chris
Posted Aug 19, 2008 at 2:03 PM | Permalink

First time I’ve ever been called an alarmist lol!

Thanks Aaron for setting it straight. Don’t quite see where bender got the idea – i think it’s clear from everything i’ve ever posted that i don’t want the ice to melt. My “gamble” was that when the ice started melting more quickly in early August, I predicted confidently that the rapid melt wouldn’t last, on the basis that it was due to temporary weather conditions. I was partially right, because it did slow down somewhat, but unfortunately the unusual weather conditions persisted and so my overall prediction (of 2008 staying on a par with 2005/6) was wrong. (Yes AndyW turns out you were right to say I was on a “sticky wicket”…..)

723. BarryW
Posted Aug 19, 2008 at 2:24 PM | Permalink

I was curious to see how 2008 loss rates were doing against 2003-2007

This graph shows the data using a loess smoothing. The gray background is the average of 2003-2007 without smoothing and the dashed gray line is the average using loess. I don’t have a good feel for how to set the loess parameters so I eyeballed the loess line against the average and used that for the span value (.2).

What I found interesting was that everyone except 2008 had made the turn, with 2008 going wide. Being at the end of the data set probably accounts for some of the differences between 2008 and the rest, but 2008 needs to start dropping soon since everyone else is going down quickly. In another 30 days the average is going to go positive.

724. Chris
Posted Aug 19, 2008 at 2:37 PM | Permalink

#715 cont’d
“The forecast is for a maximum of 19C both tomorrow and Thursday. Then finally the maximum drops: Fri 9C, Sat 7C, Sun 3C, Mon 7C. And this time I’m certain it’s for real (a couple of weeks ago the 5-day forecast predicted a drop of at least 5C which simply failed to materialise, but we’re talking a drop of 10-15C this time, which is a lot to be wrong!)”

In fact the forecast for max temps in Tiksi has now been revised to:
Wed 21C
Thu 19
Fri 9
Sat 5
Sun 2 (WITH SNOW SHOWERS!!)
Mon 4

This is quite a change considering even the minimum hasn’t been below 7C since the start of the month.

(n.b. contrast Barrow, at a similar latitude to Tiksi, which has not had a maximum above 7C since Jul 28th.)

725. bender
Posted Aug 19, 2008 at 4:43 PM | Permalink

#724
An uncharacteristic error. I read your post too quickly and assumed you were talking in terms of melt rate, not ice extent. High melt => lowering extent.
[Given the high amount of uncertainty on A in AGW, it is possible that you ARE relatively alarmist! :)]

726. markinaustin
Posted Aug 19, 2008 at 8:06 PM | Permalink

anyone watch this site?

http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+010

i have been watching it for like 3 or 4 months and this is easily the coolest month yet. should be a very low august if i am reading it right! any other opinions?

mark

727. Aaron Wells
Posted Aug 19, 2008 at 8:43 PM | Permalink

i have been watching it for like 3 or 4 months and this is easily the coolest month yet. should be a very low august if i am reading it right! any other opinions?

Yes. I track it daily. But I don’t pay much attention to any altitudes higher than the first 2 (1km and 4.4km) as they represent the closest thing to the surface temps. I personally think that there is a correlation between the anomalous spike in July temps and the high melt rates in July and carrying over into August. I know that the AMSU graph is a global average, but I also know that some of the highest anomalies have been in Siberia and are likely related to that spike.

728. TAC
Posted Aug 19, 2008 at 9:07 PM | Permalink

Preliminary Unofficial Day 232 Race Report
2008 has yet another big day, now just over 600K behind 2007.
8 20 2002 6.177813 -0.052343
8 20 2003 6.535156 -0.037500
8 19 2004 6.430469 -0.039687
8 20 2005 5.922500 -0.057969
8 20 2006 6.116563 -0.068593
8 20 2007 5.075000 -0.046563
8 19 2008 5.686250 -0.077344

729. Aaron Wells
Posted Aug 19, 2008 at 9:14 PM | Permalink

Preliminary Unofficial Day 232 Race Report
2008 has yet another big day, now just over 600K behind 2007.
8 20 2002 6.177813 -0.052343
8 20 2003 6.535156 -0.037500
8 19 2004 6.430469 -0.039687
8 20 2005 5.922500 -0.057969
8 20 2006 6.116563 -0.068593
8 20 2007 5.075000 -0.046563
8 19 2008 5.686250 -0.077344

Very odd. EXACTTLY the same area reduction as yesterday. What are the odds???

730. Posted Aug 19, 2008 at 9:46 PM | Permalink

Re #731

Remember as far as extent goes the data is pixelated so you can only lose integral numbers of ~6×4 km. So to have the same number means that the same number of pixels was lost each day, ~3223 in this case (depending on exactly what the pixel size is).

731. Michael Hauber
Posted Aug 19, 2008 at 10:57 PM | Permalink

I would make a very rough guess that each day’s value is typically within about 10% of the previous days (by using my eyeball on one of Aaron’s charts). Thats roughly a 1 in 600 chance per day of duplicating the previouis days (10% range * 2 directions * 3223 pixels). Watching the numbers for a month makes it roughly a 1 in 20 chance that one day somewhere duplicates a previous day. Watching the numbers for 7 different years over a month gives a 1 in 3 chance that a number is exactly duplicated from the previous day in one of the years.

732. AndyW
Posted Aug 20, 2008 at 12:21 AM | Permalink

I still had to cut and paste twice though as I didn’t believe my eyes…

Amazing chance in temperature over a few days in Tiksi, thanks Chris for that info. Reminds me of earlier this year where one place in the USA was 54F and 20 miles away it was over 100F (was reported on Wunderground and pardon the non Celsiusness of the figures).

Regards

Andy

733. Geoff Sherrington
Posted Aug 20, 2008 at 3:13 AM | Permalink

Re Snow at this time of the year

Melbourne in the Sth Hemi has snow down to 500m forecast tomorrow 21 Aug, which does not happen very often. So if the SH can cool and snow abnormally, why can’t the NH? At the same time, despite pervasive warming?

Steffan, Strine is a strange language. “Berrimilla” should not be confused with “Barry Miller” nor should you make jokes with “Cunnamulla”.

734. Posted Aug 20, 2008 at 5:33 AM | Permalink

Andy W #734

Thats an astonishing temperature difference and makes me wonder again if producing a world average mean temperature serves any real purpose?

IF all the weather stations remained constant in number and position.
IF exactly the same equipment was used in each one
IF the same person did the monitoring
IF the conditions around the station did not change (ie urbanisation)
IF there were sufficient stations to capture ALL the possible temp variations
Then PERHAPS there might be some small point to it all.

Tony Brown

735. BarryW
Posted Aug 20, 2008 at 7:26 AM | Permalink

Well, 2008 is now well below the min for 2006 and closing on 2005. At the present rate it will only be 5 or so days before it’s below 2005 and 2005 took about 30 days to reach that level.

736. Chris
Posted Aug 20, 2008 at 7:29 AM | Permalink

#736/#734

I understand the point you’re trying to make about the limitations of world average mean temperatures. But I don’t think it’s so astonishing to see large variations in temperature over small areas. For example if a very strong arctic cold front digs in so that just behind the boundary there’s very cold air and rain, but just in front there’s still warm air and hot summer sun, then you’d expect very different temperatures.

This doesn’t apply re: the recent heatwaves in far northern Siberia. They have been the result of a persistent pattern of low pressure hundreds of miles to the north-west and high pressure to the north-east, bringing winds from a southerly sector across a huge swathe of the Siberian coast. I don’t think you’ll find anywhere within hundreds of miles to the west or east along the coast from Tiksi that hasn’t experienced the same phenomenon. Similarly, it’s not possible for a cold plunge from the north pole to reach Tiksi (as in this weekend) without it also reaching a large swathe of the Siberian seas en route. A useful comparison would be the recent cold plunge in the Canadian archipelago, which has persistently affected a large area hundreds of miles wide (if not more)

737. Posted Aug 20, 2008 at 7:56 AM | Permalink

Chris #738

Today I walked from our village round the estuary to the town on the other side-three miles walking but only 200 yards as the sea gull flies

In the same conditions OUR side of the estuary was 5 degree F warmer than the other.

The town has a temperature and sunshine gauge so will form part of the overall national records. However is its temperature any more ‘correct'; than ours?
Also its sunshine measuring equipment is less sensitive than another towns equipment seven miles away. This other town regularly records three or four more hours sunshine daily than our local one. Surely when temperature variations are so common from one place to another only yards away, and different sorts of equuipment can record the same amounts of sunshine at wildly differing levels, it is all a bit meaningless.

I am not disputing your analogy of temp differences either side of a front but we are not dealing with this scenario in this particlar case which must be replicated millions of times worldwide.

Incidentally is it just me or is this thread becoming extremely slow to load and operate?

TonyB

738. Aaron Wells
Posted Aug 20, 2008 at 8:42 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. There was a small downward revision of the extent area this morning (~2,300 km^2).

Daily Arctic Sea Ice Extent Reduction Day 232

Arctic Sea Ice Extent Day 232

2008 Arctic Ice Extent Differences From Previous Years Day 232

Arctic Sea Ice Total Drops from Peaks Day 232

739. Chris
Posted Aug 20, 2008 at 8:43 AM | Permalink

Tony, that’s interesting re: your local area. I guess we’re talking at cross purposes here. I was dealing with the possible implication in AndyW’s post that Tiksi may not be representative of that area of the north Siberian coast, which I dispute. What you’re talking about is the usefulness or otherwise of world average temperatures. I don’t dispute any of your points about this, in fact my personal opinion is that increases in global temperature in the last 100 years have been overstated for the sorts of reasons you mention. This is partly why I’m so interested in following changes in the Arctic ice, because this is arguably a more reliable medium-term indicator of at least regional average temperature changes, than records from local stations. And yes I agree re: the slowness, this took ages to write…

740. DeWitt Payne
Posted Aug 20, 2008 at 8:55 AM | Permalink

TonyB,

Incidentally is it just me or is this thread becoming extremely slow to load and operate?

People will tell you that you don’t need a fast computer to web surf. That may be true in most instances, but on a long thread like this, a fast cpu makes a big difference. I have a Q6600 at 3.1GHz on this computer and I’m not experiencing any slowdown. On my other computer OTOH, which is much slower, keystrokes can take a second or more to appear on a long thread like this.

Projected minimum extent continues to decline, 5.09 +/- 0.45 compared to 5.12 Mm2 yesterday, but 2007 is still outside even the 99% prediction interval, barely.

741. Aaron Wells
Posted Aug 20, 2008 at 10:02 AM | Permalink

CT has Arctic ice up today!

CT ice area
region area difference anomaly
Arctic 3.681 +0.028 -1.867
Antarctic 14.607 -0.172 -0.111

742. Chris
Posted Aug 20, 2008 at 10:11 AM | Permalink

#743 Great news from the Arctic. Maybe that -2 anomaly is going to be harder to repeat than expected?
Just a minor correction: Antarctic anomaly should be +0.111 not -0.111. Still a big drop though. Both sets of figures illustrate why I’m wary of extrapolating short term trends.

743. Aaron Wells
Posted Aug 20, 2008 at 10:24 AM | Permalink

Antarctic 14.607 -0.172 -0.111

Should be:

Antarctic 14.607 -0.172 +0.111

(Thanks Chris)

744. AndyW
Posted Aug 20, 2008 at 12:20 PM | Permalink

#741

> I was dealing with the possible implication in AndyW’s post that Tiksi may not be representative of that area of the north Siberian coast, which I dispute.

No implication at all, I only said that was very interesting how it could drop a large amount in short period of time and that it reminded me of a spatial large difference from the USA this year. My example actually backs up your example!

Regards

Andy

745. DeWitt Payne
Posted Aug 20, 2008 at 12:29 PM | Permalink

It was nice to see the projected minimum for the Arctic area go up instead of down, 3.3 Mm2 today. Baby ice rallies, but has the crisis been passed? It will take a lot more than one day to be sure.

746. Posted Aug 20, 2008 at 12:44 PM | Permalink

Re #739

Incidentally is it just me or is this thread becoming extremely slow to load and operate?

Yes, doubtless when Steve returns from Italy he’ll start Run #3?

747. markinaustin
Posted Aug 20, 2008 at 1:00 PM | Permalink

relatively reasonable article…..

http://www.yaleclimatemediaforum.org/features/0708_arctic_sea_ice.htm

thoughts?

748. DeWitt Payne
Posted Aug 20, 2008 at 2:28 PM | Permalink

One final point: While Arctic ice has been declining, Antarctic sea ice has been increasing recently. But changes at the bottom of the world are well within the range of natural variability, Alley said. In contrast, the Arctic changes under way are far outside of it.

[my emphasis]

On what time scale, since 1979? According to what data set? Here’s a report from the first half of the twentieth century before satellite monitoring, referring to the warming that started in the late 19th or early 20th century:

…the salty Atlantic water penetrated further into the Arctic to such a degree that, for example, the average length of the coal shipping season at Spitsbergen almost doubled in length, from 95 days during 1909-12 to 175 days during 1930-38.

It’s now around 100 days, for tourism anyway. The coal mines aren’t in business anymore.

749. TAC
Posted Aug 20, 2008 at 9:08 PM | Permalink

Preliminary Unofficial Day 233 Race Report
2008 has a slow day, losing ground and now back to nearly 650K behind 2007.
8 21 2002 6.149219 -0.028594
8 21 2003 6.523125 -0.012031
8 20 2004 6.360938 -0.069531
8 21 2005 5.907344 -0.015156
8 21 2006 6.082500 -0.034063
8 21 2007 5.009531 -0.065469
8 20 2008 5.658750 -0.025156

750. Aaron Wells
Posted Aug 21, 2008 at 9:08 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. There was a small downward revision of the extent area this morning (2,187 km^2). This day was a huge drop in daily area reduction. We are due for another inspiring message from Jeez encouraging the baby ice to “go not gently into that good night”!

Daily Arctic Sea Ice Extent Reduction Day 233

Arctic Sea Ice Extent Day 233

2008 Arctic Ice Extent Differences From Previous Years Day 233

2007 manages to fend off 2008 from passing it for total drop from peak!

Arctic Sea Ice Total Drops from Peaks Day 233

According to this link to athropolis (click on August) tomorrow is the last day of 24 hours of sun. Starting on Saturday, the sun will begin to set for a longer period each day. This should be a critical point in the ice melt and the extent area reduction.

751. Aaron Wells
Posted Aug 21, 2008 at 9:20 AM | Permalink

Starting on Saturday, the sun will begin to set for a longer period each day. This should be a critical point in the ice melt and the extent area reduction.

I should clarify that this statement applies to the circle at the 78 degree north latitude (which is around where the ice extent edge is). The sun won’t set at the north pole until around Sept. 24th.

752. Real Richard Sharpe
Posted Aug 21, 2008 at 9:35 AM | Permalink

Aaron says:

We are due for another inspiring message from Jeez encouraging the baby ice to “go not gently into that good night”!

Well, while one line is:

Do not go gentle into that good night

The first stanza is:

Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.

Which really is a conflicting message for the baby ice!

753. DeWitt Payne
Posted Aug 21, 2008 at 10:33 AM | Permalink

CT ice area 8/20/2008
region area(Mm2) difference anomaly
Arctic 3.635 -0.046 -1.886
Antarctic 14.488 -0.119 0.043

Arctic area loss rate reached its maximum on 8/7 and has been declining ever since. However, it’s running over 20,000 km2/day greater than the average, or about two weeks behind the average rate curve. From this date, the average remaining loss expected is about 0.5 Mm2 which would give a minimum of 3.1 Mm2. However, if the loss curve remains two weeks behind, the loss would be closer to 0.9 Mm2, or a minimum of 2.7 Mm2. Splitting the difference gives 2.9 Mm2 or about 0.1 Mm2 less than 2007. Prognosis for baby ice area: terminal.

754. Chris
Posted Aug 21, 2008 at 11:57 AM | Permalink

#755 “Prognosis for baby ice area: terminal”

I think there’s a good chance you may be pleasantly surprised in the next week or so. The north pole has got really cold now: a (winter) low which developed there in the last couple of days has brought lots of snow (visible on CT satellite), temperatures as low as -5C at several nearby stations (http://www.weatheroffice.gc.ca/data/analysis/935_100.gif ) and obviously a reduction in the already low insolation. The webcam (towards Greenland I believe) shows a latest temperature of -8C (http://www.arctic.noaa.gov/latest/noaa1.jpg ). The cold which had extended towards Greenland, then the Canadian Archipelago and Beaufort Sea, has now reached the Kara Sea as well, and as I have highlighted in the last couple of days, the key source of the recent rapid melt i.e. the warm winds from Siberia are finally being cut off by the low currently extending eastwards across the Siberian seas and bringing the wintry conditions in its wake.

For those of you that think it’s far-fetched to think winter may be setting in early….. I guess many of you would not dispute that the 2008 melt has been tracking the 2004 melt in the last few weeks? If so you may be interested to read the following from the NOAA Arctic pages re: “The short Arctic Summer of 2004″ http://www.arctic.noaa.gov/essay_untersteiner3.html

755. Chris
Posted Aug 21, 2008 at 12:20 PM | Permalink

I’m also going to recycle my figures from an earlier post one more time, which are the “NoPol” i.e. high latitude MSU temperature anomalies averaged for June and July since 2000. What this says to me is that the overall “fundamentals” of the temperatures in the regions surrounding the Arctic have been relatively cool this summer (hence similar figure to 2004) and so the reasons for the almost-repeat of 2007 have been a combination of thinned ice and more anomalous winds, rather than regional warming. Therefore, once the anomalous winds dissipate, and given that the sea temperatures are cooler than last year overall in the Arctic (certainly Siberian seas/Laptev/Chukchi) the onset of winter could be surprisingly severe. Furthermore, if the winter turns out to be a cold one generally, and the winds are more “normal” next summer, then the implication from 2008’s performance is that 2009 summer ice could be surprisingly persistent. Of course, I’m jumping ahead a bit here… better wait and see if melt really does start to bottom out properly in the next couple of weeks….. (I think extent in particular could continue to take some knocks from the dispersal/melt of large areas of thin ice around the periphery e.g. East Siberian sea, even as (CT) area starts to grow closer to the pole)

2000 0.27
2001 0.68
2002 0.79
2003 0.85
2004 0.53
2005 1.04
2006 0.83
2007 1.47
2008 0.52

756. Posted Aug 21, 2008 at 12:27 PM | Permalink

Re #756

Chris the melt stopped at about this date last year, so from the sea ice perspective the best that can happen is that it stops melting now, otherwise any further melting will eat in to the remaining difference (~0.6 Mm^2). This year is already below the trend in sea ice minimum area prior to last year. Last year although the melt stopped earlier than usual it didn’t start to refreeze until the end of september so an early end to melting (should it occur) wouldn’t necessarily presage an early winter.

757. BarryW
Posted Aug 21, 2008 at 1:41 PM | Permalink

Re 758

I don’t think that’s right. The extent loss (see Aaron’s graph) stopped about day 267 for last year with the first positive gain at day 244. 2005 also has a dip at 265 and first positive gain at day 245. Everything is slowing quickly from this point on though.

My estimate is that there is 1.404 left to the 2007 minimum (5.658 (2008 now) to 4.254 (2007 minimum). If it was melting at my present smoothed estimate (.06) there’s about 23 days left til 2008 passes 2007. Average the rate out over 30 days (assuming the melt is going to stop at about the same time as the other years) and I get 0.91, so I’d guess the extent minimum at 4.7. if 2008 follows the mean loss from now (-0.546) it would be about 5.1.

758. DeWitt Payne
Posted Aug 21, 2008 at 2:30 PM | Permalink

Phil is correct on this point. The area loss stopped about now while the extent continued to drop. However, he’s wrong about concentration here.

Current average concentration ~65% whereas it didn’t get below 70% last year.

If the area stopped decreasing but the extent continued to decrease, the concentration went up. Area at this time last year was about 3.1 +/- 0.1 and the extent was 5.01 so concentration was 62 +/-2% compared to 64% this year. Concentration at extent minimum in 2007 was indeed over 70%. Concentration hasn’t changed much over the last few days, but it takes more than that to establish a change in trend.

759. Posted Aug 21, 2008 at 2:33 PM | Permalink

Re #759

The extent isn’t a measure of melt total area is, that stopped about this date last year, the extent continued to fall as a result of the consolidation by winds and currents.
This year’s ice is about 600,000Mm^2 away from last year’s minimum but is more spread out, a year ago the concentration was ~73% whereas now it’s ~65%.

760. DeWitt Payne
Posted Aug 21, 2008 at 2:38 PM | Permalink

Phil,

I can only get 73% if I divide this years area by last year’s extent. I’m curious how you do it.

761. Lurker Bill
Posted Aug 21, 2008 at 2:46 PM | Permalink

Quick question from an interested bystander. In comparing ’07 with ’08, wouldn’t it be more accurate to factor in concentration? I mean, if we’re trying to get a handle on the future of the arctic ice, wouldn’t that be indicative?

762. Chris
Posted Aug 21, 2008 at 2:54 PM | Permalink

#759 BarryW

Phil is referring to Ice Area (as calculated at Cryosphere Today)

I think your calculations re: extent make sense from a purely average-based statistical point of view. However, if you look at previous years, they don’t display soft curves but quite sudden changes e.g. 2004 with which I made the comparison http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm I’ve been trying to add to the debate by trying to look in more detail at the reasons for such changes “on the ground”, and I think it is important to do this with climate in general. In other words, if the current conditions “on the ground” are not average, then 2008 will not track the average, whatever has happened in recent weeks. (Thus with ice area, it was crashing in the week leading up to this date last year, but stabilised after, so a prediction based on that week would have been totally wrong.)

Of course, because it’s so hard to understand what actually happens on the ground, you’re still probably more likely to be right than me :)

By the way (re: melting) if increasing cold at the pole makes the ice in that area more concentrated due to refreezing, but the patchier ice at the periphery of the Arctic continues to disperse/melt, then area will stabilise (or even increase) while extent continues to decrease.

763. DeWitt Payne
Posted Aug 21, 2008 at 2:56 PM | Permalink

Lurker Bill,

Well, I always assumed that concentration was area divided by extent and since we are tracking both area and extent, concentration could be left, as they say in textbooks, as an exercise for the reader. But if Phil is correct, concentration is a separate measure and I’d like to know where or how he gets it.

764. Chris
Posted Aug 21, 2008 at 3:23 PM | Permalink

#763 Lurker Bill

First of all I’d echo what Dewitt says above (#765).

You can get a feel for concentration by eye-balling the following: http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=20&fy=2007&sm=08&sd=20&sy=2008

To my mind this shows 2 key things:

(1) There’s a lot of low concentration ice at the periphery, hence Phil can claim the overall concentration is relatively low, and I have to concede that extent may have some way to drop still.

but (2) the ice around the pole itself appears to be significantly more concentrated now than at this point last year.

In terms of the future of the Arctic ice, I would say that for it to look the way it does now, despite the 2007 legacy and the north Canadian (July) /north Siberian (August) heatwaves, gives significantly more cause for optimism than the NSIDC forecasts at the start of the season (or even a couple of weeks ago – 2007 and 2008 looking “neck and neck”)

765. BarryW
Posted Aug 21, 2008 at 6:16 PM | Permalink

Re 760, 761, 764

Sorry, I stand corrected. You’re talking apples and oranges and I was talking kumquats.

Chris

By the way (re: melting) if increasing cold at the pole makes the ice in that area more concentrated due to refreezing, but the patchier ice at the periphery of the Arctic continues to disperse/melt, then area will stabilise (or even increase) while extent continues to decrease.

That’s what I would think would have to happen if extent is continuing to fall while area loss has stopped, unless it’s consolidation of the remaining ice by wind or current as Phil said. Would low concentration make consolidation more likely?

Of course, because it’s so hard to understand what actually happens on the ground, you’re still probably more likely to be right than me

Maybe, but trying to understand what the drivers are is more important than trying to play “Let’s Make a Deal” with baby ice by guessing what the extent is going to be. I’m just playing games with graphs.

766. Jon
Posted Aug 21, 2008 at 6:45 PM | Permalink

BarryW (#759) and others:

It is indeed possible to be accumulating ice Northward while continuing melt in the periphery leads to extent loss.

767. TAC
Posted Aug 21, 2008 at 9:05 PM | Permalink

Preliminary Unofficial Day 234 Race Report
2008 has a moderate day, now over 660K behind 2007.
8 22 2002 6.130156 -0.019063
8 22 2003 6.520156 -0.002969
8 21 2004 6.275625 -0.085313
8 22 2005 5.901563 -0.005781
8 22 2006 6.061250 -0.021250
8 22 2007 4.948438 -0.061093
8 21 2008 5.610313 -0.046250

768. DeWitt Payne
Posted Aug 21, 2008 at 9:34 PM | Permalink

The rate of change of the loss rate appears to be accelerating only a little later than expected. Projected minimum has stabilized for the moment at 5.1 +/- 0.4 Mm2 on 9/15, less than four weeks from now.

769. Posted Aug 21, 2008 at 10:28 PM | Permalink

Re #760

Phil is correct on this point. The area loss stopped about now while the extent continued to drop. However, he’s wrong about concentration here.

Current average concentration ~65% whereas it didn’t get below 70% last year.

You’re right, I’ve been following the concentration for some time and it has consistently been lower this year, when I looked at it last week it was about 72% for 07 and at the minimum last year it was ~70% and I hadn’t noticed that it did drop below 70% for a short while last year.

If the area stopped decreasing but the extent continued to decrease, the concentration went up. Area at this time last year was about 3.1 +/- 0.1 and the extent was 5.01 so concentration was 62 +/-2% compared to 64% this year. Concentration at extent minimum in 2007 was indeed over 70%. Concentration hasn’t changed much over the last few days, but it takes more than that to establish a change in trend.

Re #766

but (2) the ice around the pole itself appears to be significantly more concentrated now than at this point last year.

I don’t see this perhaps we’re talking about different things, looking at these images from Uni Bremen:
Today
Last year
If anything there appears to be a ‘tongue’ of lower concentration ice along the 150ºE which extends as far as the grey dot at the pole this year.

770. Posted Aug 21, 2008 at 10:32 PM | Permalink

I tried to respond to some of the above but got eaten by the spam filter, hopefully it will make it through?

771. AndyW
Posted Aug 22, 2008 at 12:58 AM | Permalink

Are people using these maps

to give indications of the concentrations and area of subsequent possible melt?

Due to the cold weather up there currently 2008 has now lapsed into a more normal melt pattern for this time of year I think, I doubt we will see more than 1 or 2 60k + days from now on in. I’m going to once again say more than ever I don’t believe the 140K/650 couple of days we saw earlier, I think the 140K was far too large and was subsequently adjusted by the very small figure the day after.Biggest day of the melt seasonr to the smallest in 2 days? Nah….

772. Flanagan
Posted Aug 22, 2008 at 3:02 AM | Permalink

Hi Andy!

It’ true that temperatures now follow a pattern which could make us a little bit more optimistic. On the other hand, as can be seen on cryopshere e.g., the ice has loads of regions of low concentration (much more than last year at same julian day), especially on the borders, so that the winds may play a role in the melt. But I do admit that the brutal changes in the ice losts don’t seem quite realistic…

773. BarryW
Posted Aug 22, 2008 at 8:01 AM | Permalink

Extent loss appears to be decelerating, but still above the average for this date. Looks like it’s still following 2004’s right now.

774. Aaron Wells
Posted Aug 22, 2008 at 8:32 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. There was a small upward revision of the extent area this morning (~1,100 km^2).

Daily Arctic Sea Ice Extent Reduction Day 234

Arctic Sea Ice Extent Day 234

2008 Arctic Ice Extent Differences From Previous Years Day 234

2007 continues to fend off 2008 from passing it for total drop from peak!

Arctic Sea Ice Total Drops from Peaks Day 234

775. DeWitt Payne
Posted Aug 22, 2008 at 10:16 AM | Permalink

CT ice area
region area(Mm2) difference anomaly
Arctic 3.651 0.016 -1.826
Antarctic 14.392 -0.096 -0.195

A gain in area for the Arctic. Projected minimum area remains 3.3 Mm2 for the third day in a row. Baby ice is still in critical condition, but isn’t getting worse for the moment. Arctic ice concentration, defined as CT ice area divided by JAXA extent, is over 65% for the first time in about a week.

776. Chris
Posted Aug 22, 2008 at 10:35 AM | Permalink

DeWitt – I appreciate your caution. But shouldn’t projected minimum have gone up at least a little, considering ice area has seen essentially no net melt in the last 3 days? (Also considering there was no significant net melt after this date last year?)
Aug 19th 2008: 3.653
Aug 22nd 2008: 3.651

I would say 3.3 now looks towards the lower limit of projections……. the upper limit being 3.635 precisely – i.e. yesterday!!!
Area only needs to stay above 3.5 for it to have grown 20% as compared with the 2007 minimum (2.92) which is a respectable comeback, even if some way short of 2005.

777. Aaron Wells
Posted Aug 22, 2008 at 10:42 AM | Permalink

A gain in area for the Arctic.

At the risk of speaking too-soon (and ruining the chances for the baby ice) this may be a harbinger of hope for the baby ice. This makes 2 days out of the past 3 where CT has reported an actual gain in ice area rather than a loss. Also, this make a net loss of only 2,000 km^2 over those 3 days. The baby bergs are not out of the woods yet, but there is hope, especially given that starting tomorrow the areas around the ice extent edges will begin to see periods of darkness, first for about a half-hour, ten increasing a little each day.

778. DeWitt Payne
Posted Aug 22, 2008 at 10:47 AM | Permalink

Chris,

My projected minimum is a crude estimate based on my projected JAXA minimum extent and the assumption of constant concentration (CT/JAXA). The concentration hasn’t changed much recently so the projected minimum has been constant as well. If the concentration goes up as it apparently did last year (still waiting to see if Phil’s answer will be released from spam limbo, MrPete???), the projected minimum will increase too. I don’t have any statistics on concentration, so I can’t assign any bounds to the projection.

Speaking of spam limbo, now that we don’t have an Unthreaded, how do we notify the man in charge that there is a problem? Is Steve’s yahoo.ca email address being monitored by anyone in near real time?

779. DeWitt Payne
Posted Aug 22, 2008 at 1:29 PM | Permalink

I’ve plotted the annual average Arctic ice extent for 2003 to 2007 and the YTD average extent for 2003 to 2008. I think the average extent (area would be better but I don’t have the data) better reflects the average temperature than either max, min or (max+min)/2. The YTD number for 2007 doesn’t yet include the extended stay near the minimum that makes the full year average lower than 2006. 2008 looks likely to have significantly higher average extent than 2007. The real test will be 2009 and 2010. Then we will start to see if this is just a replay of 1910 to 1940 or a fingerprint of (A)GW.

I’m still waiting for any comment about why the relative lack of ice near Spitsbergen (78 N latitude) in 1930 to 1938 compared to earlier in the 20th century and today is not a valid indicator of Arctic ice extent then vs. now.

780. Posted Aug 22, 2008 at 2:37 PM | Permalink

Re #781

I’m still waiting for any comment about why the relative lack of ice near Spitsbergen (78 N latitude) in 1930 to 1938 compared to earlier in the 20th century and today is not a valid indicator of Arctic ice extent then vs. now.

I’d say that the exact position of the ice in the North Atlantic is governed by the balance between the warm water from the Atlantic and seems to be in approximately the same position from year to year, the recent change in the ice extent in recent years has been to the Pacific side (Maslowski’s presentation which I’ve linked above discusses this). This comparison of the images at the minima for the satellite era shows relatively little variation on the Atlantic side.

Posted Aug 22, 2008 at 5:04 PM | Permalink

According to the Anchorage NWS Ice Desk:

FORECAST VALID…WEDNESDAY AUGUST 27 2008

ANALYSIS CONFIDENCE…LOW-MODERATE

SYNOPSIS…A HIGH PRESSURE CENTER CURRENTLY OVER THE ARCTIC COAST
WILL CONTINUE TO DISSIPATE ON SATURDAY. A DEVELOPING LOW IN THE HIGH
ARCTIC ON SATURDAY MOVES INTO THE NORTHERN CHUKCHI SEA ON SUNDAY.

-ARCTIC OCEAN-
-BEAUFORT SEA-
-CHUKCHI SEA-

PKZ225-CAPE THOMPSON TO CAPE BEAUFORT-
PKZ230-CAPE BEAUFORT TO POINT FRANKLIN-
PKZ235-POINT FRANKLIN TO CAPE HALKETT-
PKZ240-CAPE HALKETT TO FLAXMAN ISLAND-
PKZ245-FLAXMAN ISLAND TO DEMARCATION POINT-

THE MAIN ICE EDGE LIES FROM 72.4N 158W TO 70.7N 163W TO 72.2N 170W TO
73N 177.3W AND SOUTHWEST TO WRANGEL ISLAND. THE EDGE IS MAINLY 3 TO 7
TENTHS FIRST YEAR THIN ICE…YOUNG…NEW.

FORECAST THROUGH WEDNESDAY…
FOR THE MAIN LOBE OF ICE CENTERED AT 71.5N 163W EXPECT A NORTHWARD
RETREAT OF 20 TO 30 NM BY WEDNESDAY. WEST OF 165W AND NORTH OF 70N
EXPECT MODERATE TO STRONG NORTH WINDS SUNDAY MORNING THROUGH TUESDAY
WITH TEMPERATURES DECREASING TO THE UPPER 20S. SOME NEW ICE MAY FORM
NORTH OF 72N BY WEDNESDAY.

782. Kimberley Cornish
Posted Aug 22, 2008 at 5:26 PM | Permalink

#754
Surely the eponymous Robert FROST would be a more relevant poet to quote from on this?

783. pochas
Posted Aug 22, 2008 at 6:34 PM | Permalink

Whose woods are these? I think I know…

784. Real Richard Sharpe
Posted Aug 22, 2008 at 8:02 PM | Permalink

Whose woods these are I think I know
His house is in the village though
He will not see me stopping here
To watch his woods fill up with ice? No, snow!

785. BarryW
Posted Aug 22, 2008 at 8:47 PM | Permalink

I think my last post got eaten by a spam filter.

This link has historical area data, but not for this year, on the ftp site if anyone is interested, or am I duplicating know info?

http://www.ifm.uni-hamburg.de/~wwwrs/seaice/amsr-e.html

786. MattN
Posted Aug 22, 2008 at 9:14 PM | Permalink

Anyone else like to see an Antactic-watch thread?

I’d like some insight to the jagged saw-tooth growth rate down there over the last month. What once appeared to be a sure-fire new record high is not-so-sure anymore….

787. DeWitt Payne
Posted Aug 22, 2008 at 10:30 PM | Permalink

BarryW,

In fact, your link to the University of Hamburg has data through 7/31/2008 on the ftp site in the .txt files. Unfortunately it is only updated once/month in the middle of the month so it can be up to six weeks behind. It also apparently uses a different algorithm for extent than JAXA and uses a different satellite image for area than CT so the numbers are not the same. Concentration, for example is usually in the range of 85 to 95% compared to the 65% currently using JAXA and CT. Minimum extent and area for 2007 were 3.53 and 3.26 Mm2 compared to 4.25 and 3.0 for JAXA and CT. On 7/31/2008 U.Hamburg result was 5.39 Mm2 area and 6.10 Mm2 extent compared to 5.22 Mm2 area for CT and 7.20 Mm2 extent for JAXA. Area seems to be pretty close. I’ll check to see if the ratio of UH to CT is constant.

788. BarryW
Posted Aug 23, 2008 at 6:01 AM | Permalink

DeWitt,

I find these sites frustrating in that they provide graphs and images, which are fine as far as they go, but don’t provide the data in a textual form for their graphs, such as the JAXA csv file for the extent. Even when you find the data it’s usually historical or delayed.

Interesting that the results are so far off.

789. Aaron Wells
Posted Aug 23, 2008 at 9:00 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. Yesterday’s extent area reduction was 56,250 km^2 (which is up a little over the previous day’s reduction of 45,157, and well above the average of the previous 6 years, 33,829).

Daily Arctic Sea Ice Extent Reduction Day 235

Arctic Sea Ice Extent Day 235

2008 Arctic Ice Extent Differences From Previous Years Day 235

2007 continues to fend off 2008 from passing it for total drop from peak!

Arctic Sea Ice Total Drops from Peaks Day 235

790. TAC
Posted Aug 23, 2008 at 9:54 AM | Permalink

Updated Unofficial Day 235 Race Report
2008 has a moderate day, back to about 650K behind 2007.
8 23 2002 6.109688 -0.020468
8 23 2003 6.482188 -0.037968
8 22 2004 6.208594 -0.067031
8 23 2005 5.883750 -0.017813
8 23 2006 6.041563 -0.019687
8 23 2007 4.908438 -0.040000
8 22 2008 5.555156 -0.056250

(with apologies for the lateness) :-)

791. Chris
Posted Aug 23, 2008 at 10:20 AM | Permalink

#788 Matt – I’m also intrigued by the Antarctic. I looked at the issue briefly a couple of days back, and concluded that storms may have had something to do with it, though I’m not quite sure how to explain the mechanism (on the face of it, if ice is blown around/compacted/dispersed/fractured by storms, extent times concentration i.e. area (?) shouldn’t vary as much as extent….? though n.b. it clearly does c.f. early August in the Arctic….) There was definitely an intense storm that came and went round about the same timeframe; also this coincided with a particularly cold plunge in New Zealand and Australia (NZ saw record amounts of snow). It seems plausible that NZ’s gain (of cold) was Antarctica’s loss hence the falls in area following the gains? And/or maybe the winds from Antarctica blew lots of newly-formed ice out to the open ocean to melt en route to NZ? Lots of questions, uncertain answers……..
There definitely seems to have been a lot of volatility around Antarctica recently, with the ice going up and down, as well as temperatures and storm activity. My gut feeling is that this could represent an overall cooling of the SH oceans, if more and more warmer water/air was being mixed with Antarctic ice/water/air yet total Antarctic ice stayed close to normal.
So it could be that the Antarctic ice has been “held back” the last couple of months by warmer waters – certainly MSU showed SH ocean temps going up quite a lot in July, and the Nino indicators show the same thing. However…….. what causes what?
Is it possible that the mixing I described above has sent large amounts of subsurface/deep cold water northwards? (following a period of lack of mixing hence less cold currents?) Certainly, there’s some anecdotal evidence of cold SST anomalies lurking in the equatorial pacific not far from the surface, and a hint they might have just started growing. Overall, of course , the Nino indicators show warming such that we’re not far off a mild El Nino re: equatorial east pacific SST anomalies (you can see this by eye-balling any recent SST anomaly map for the area). At the same time……… this has receded slightly in the last week, while the SOI index has turned significantly upwards, such that the trade winds are picking up again which could encourage cold upwelling to return. There’s even a hint that the 30-day SOI could be up to +5 by the end of the month, which would be a signal of returning La Nina!
This is the issue that most fascinates me at the moment. I find it very striking how autumn 2007 brought big jumps in Antarctic ice alongside big jumps towards La Nina, and I wonder to what extent either/both is possible again a year later. The experts are predicting mainly neutral conditions, with La Nina essentially ruled out, and there’s even an expert working for GWO predicting the strongest El Nino since 1998.
On the other hand, “back-to-back” La Nina has a precedent – 1999 and 2000. But El Nino/La Nina are still very poorly understood and expert forecasts have frequently been very wrong.
A return to strong La Nina, especially if it brought global temperatures even lower than earlier this year, would be dynamite to the current AGW debate. On the other hand, a strong(-ish) El Nino that failed to bring significant warming would also have very interesting implications. Of course, if there were to be a strong El Nino that brought a further step change upwards in global temperatures, then this would also be dynamite to the debate but not the eventuality I would choose…..
Sorry for the significant degree of speculation in this post, but hope it might help spark some extra insight.

792. Chris
Posted Aug 23, 2008 at 10:25 AM | Permalink

I’ll let DeWitt Payne report today’s exact figures from CT but looks like more good news from the Arctic……

793. DeWitt Payne
Posted Aug 23, 2008 at 10:39 AM | Permalink

CT sea ice area update
region area(Mm2) difference anomaly
Arctic 3.669 0.018 -1.769
Antarctic 14.354 -0.038 -0.289

I’m still in the process of massaging the U.Hamburg data (University of Hamburg, Institute of Oceanography, Gunnar Spreen and Lars Kaleschke). The average area from those data has a minimum on 9/5 and the loss from 8/22 to 9/5 is 0.215 Mm2. That projects the minimum at 3.45 Mm2. My projected minimum is 3.35 Mm2 and rising. Obviously, the upper limit is the most recent minimum of 3.635 Mm2. Baby ice has staged a remarkable rally and I am upgrading its condition from critical to guarded.

UHam has the Antarctic extent and area data from 2002 to 7/31/2008 as well and it looks like a relatively flat but fluctuating area near the peak is normal.

794. Chris
Posted Aug 23, 2008 at 10:50 AM | Permalink

#771 Phil Re #766

“I don’t see this perhaps we’re talking about different things, looking at these images from Uni Bremen:
Today
Last year
If anything there appears to be a ‘tongue’ of lower concentration ice along the 150ºE which extends as far as the grey dot at the pole this year.”

Sorry Phil I wasn’t able to view your post before. I was already aware of the “tongue” of lower concentration ice you mentioned. However, maybe we’ll have to agree to disagree about the Bremen images. To me they clearly show significantly more high concentration ice north of 80 degrees now compared with a year ago.
Plus a significant proportion of the high concentration ice is in areas characterised as “baby ice” following last summer (i.e. to top left, top right, and bottom right – seeing as I can’t use compass points since every direction is south!)

795. Chris
Posted Aug 23, 2008 at 10:55 AM | Permalink

#796 cont’d…….
Of course I could have used longitudes like yourself rather than “top left” etc :)

796. Aaron Wells
Posted Aug 23, 2008 at 9:39 PM | Permalink

Check out the new ice that has formed in the Hudson Bay:

Cryosphere Today Still image 08/22/08

If you play the animation you see that the ice popped up a couple of days ago.

797. Posted Aug 23, 2008 at 10:14 PM | Permalink

Re #798

Actually I think you’ll find that’s cold cloud tops, it certainly doesn’t show on radar:

798. DeWitt Payne
Posted Aug 23, 2008 at 10:56 PM | Permalink

Looking at the exponentially smoothed JAXA extent loss rate for 2008 and comparing the the smoothed rate for the average of 2002 to 2007 adjusted to minimum extent on the same day gives an alternative way of extrapolating the date and value of minimum extent. This method doesn’t work until the loss rate starts to drop rapidly. The value today is 4.7 Mm2 on 9/24 compared to 5.07 on 9/15. The smoothed extent loss rate continues to be above average, exceeded only by 2004.

Because there is a large mismatch in dates of minimum extent, the area remaining method I have been using may no longer be reliable. I think the prediction interval estimates are even less reliable so I will only report the two estimates from now on.

799. Aaron Wells
Posted Aug 23, 2008 at 10:58 PM | Permalink

Actually I think you’ll find that’s cold cloud tops, it certainly doesn’t show on radar:

http://ice-glaces.ec.gc.ca/prods/WIS31SD/20080823180000_WIS31SD_0003931256.gif

While you may be right, the latest image from University of Hamburg shows some sort of indication of something in the Hudson Bay. Perhaps that is cloud tops as well. (zoom in to the Hudson Bay). There seems to be a hint of white color lining the coastline of parts of the bay as well. Perhaps its just a glitch.

University of Hamburg Map Sea Ice concentration for 08/24

800. Aaron Wells
Posted Aug 23, 2008 at 11:11 PM | Permalink

This sea surface temperature map suggests that ice formation in the Hudson Bay would be extremely unlikely:
UNISYS Current Sea Surface Temperature Plot

So, I withdraw my earlier theory, and concur with Phil that it is likely cloud tops.

801. Vincent Guerrini Jr
Posted Aug 23, 2008 at 11:15 PM | Permalink

oh oh… looks like AGW = RIP?
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg Its ice not cloud

802. Aaron Wells
Posted Aug 23, 2008 at 11:26 PM | Permalink

While the ice area (CT-type) has stopped temporarily (there have been gains 3 out of the past 4 days for a net increase of 16,000 km^2 over those 4 days), all of the sea surface temperature maps show that the water in the Hudson Bay is much too warm to support ice formation. I’d like to believe it is ice, but I don’t think so now.

803. WhiteBeard
Posted Aug 24, 2008 at 12:40 AM | Permalink

# 803 Vincent Guerrini Jr,

Could those items between 55 and 60 North in Hudson’s Bay have any relation to the patches to the east of Hokkaido and Honshu in the Sea of Japan, or might the stuff along the Bay’s southeastern coast be something like the similar, but more solid appearing, stuff on the western coast of the Iberian Peninsula? Notice the edge effect of water to the west of a coastline on the U Hamburg rendering.

804. AndyW
Posted Aug 24, 2008 at 1:28 AM | Permalink

For ice around Canada, including Hudson bay I think this map is a better bet than the CT or other maps

As you can see the large mass of ice on the CT map does not exist here.

Regards

Andy

PS 2008 has definitely cracked now (pardon the pun)but is still managing to pull out slightly on 2005 and 2006. I would say we are all in agreement now that 2008 will clearly be the 2nd smallest extent and area on record but nowhere near 2007.

805. AndyW
Posted Aug 24, 2008 at 1:31 AM | Permalink

Also, what do people think of the chances of the NW and NE passages being open this year ? The NE is looking pretty liquid at the moment …..

806. TAC
Posted Aug 24, 2008 at 4:11 AM | Permalink

Preliminary Unofficial Day 236 Race Report
2008 has another moderate day, now about 640K behind 2007.
8 24 2002 6.117188 0.007500
8 24 2003 6.448125 -0.034063
8 23 2004 6.135313 -0.073281
8 24 2005 5.853125 -0.030625
8 24 2006 6.043438 0.001875
8 24 2007 4.875625 -0.032813
8 23 2008 5.514844 -0.040312

807. Chris
Posted Aug 24, 2008 at 4:57 AM | Permalink

I’m going to be following with interest 2008’s continued progress towards the 2005 extent minimum (5.315 on 22nd Sep). Currently 2008 still has to lose 0.20. On the one hand:

– there is currently a relatively large amount of low concentration ice on the periphery which is vulnerable to continued melt/dispersal/consolidation all of which could signal continued significant extent drops;
– the recent downward trend in extent has been steeper than the average.

But on the other hand:

– very slow finishes to the season are possible e.g. 2006 lost just 0.26 between 24th August and 14th September (minimum 5.782);
– recent changes in weather patterns have brought a sharp change in the ice area trend, and this may be seen in the ice extent trend too after a lag.

Personally I think it’s very unlikely that 2008 could still end up not beating 2005’s minimum. However, there may still be a realistic chance that it ends up over 5.2 i.e. within 2% of 2005’s minimum or ~1 million km2 / 20% greater than 2007.

In this scenario I would put a subtly different spin on AndyW’s statement in #806, such that 2008 would have

– *only just* the 2nd smallest *minimum* extent on record (the average extent over the melt season would seem to be still bigger than in 2005 so far)

– the 2nd smallest *minimum* area on record (again, average area over the melt season looks to be still comparable to 2005, and if the current recovery continues then the anomaly could soon be back at 2005/2006 values. Also, an anomaly of > -1.5 in October would put 2008 as much as 1.5 million km2 or ~35% ahead of 2007 again – http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.jpg)

808. John Lang
Posted Aug 24, 2008 at 8:07 AM | Permalink

If you want to double-check any of the radar-software-generated ice maps, you can use the MODIS satellites. The MODIS Terra and Aqua satellites provide real-time actual satellite pics across the whole planet (polar orbits) every 5 to 10 minutes.

The downside of the MODIS sats are they are a little hard to use initially and they are visible satellite pics which means they do not work at night and clouds can get in the way. The upside is that they are REAL pictures, not generated by a software program written and adjusted by a warmer from the NSIDC.

There are various false color options which allows one to separate ice from cloud cover and resolutions go from 4kms down to 250M.

Northern Hudson Bay from yesterday. No good pics from the middle of Hudson Bay yesterday but there is a very intense low pressure right over it which is probably giving the false ice readings but you never know.

NorthWest Passage – cloud covered for several weeks now but you can see there is new ice forming in the passage right now which is bad news for any yachts trying to get through.

All Modis pics from today.

http://rapidfire.sci.gsfc.nasa.gov/realtime/

809. John Lang
Posted Aug 24, 2008 at 8:09 AM | Permalink

If you want to double-check any of the radar-software-generated ice maps, you can use the MODIS satellites. The MODIS Terra and Aqua satellites provide real-time actual satellite pics across the whole planet (polar orbits) every 5 to 10 minutes.

The downside of the MODIS sats are they are a little hard to use initially and they are visible satellite pics which means they do not work at night and clouds can get in the way. The upside is that they are REAL pictures, not generated by a software program written and adjusted by a warmer from the NSIDC.

All Modis pics from today.

http://rapidfire.sci.gsfc.nasa.gov/realtime/

810. Chris
Posted Aug 24, 2008 at 8:19 AM | Permalink

Very big downward revision in ice extent today (feel like it’s to punish me for over-optimism in my previous post maybe….)

Was 5.514844
Now 5.500156

I’m worried that the current polar low, although it’s bringing cold and snow, might also be dispersing the ice? I’d say the next couple of days very unpredictable for extent, could be anything…..

811. BarryW
Posted Aug 24, 2008 at 8:52 AM | Permalink

Re 809

- very slow finishes to the season are possible

2005’s loss increased about a month from now otherwise it was tracking close to the 2003-2007 average so a faster finish is possible too.

2007 is getting close to the average’s min (5.470437) and the loss is still tracking like 2004/2007. Average loss for this date is -0.0337814.

812. David Smith
Posted Aug 24, 2008 at 8:59 AM | Permalink

Re #810 John, are the pinkish colors in the false Arctic images indicating fog (“sea smoke”)? They seem to have expanded in recent days, which I presume is normal for late August as radiative cooling begins to dominate. Thin fog does a pretty good job of blocking sunlight when the sun angle is low, yet allows some surface-generated IR to radiate upwards into space.

I also presume that, at this late date, most of the remaining melting comes from heat stored in the water earlier this summer rather than from current insolation.

My key interest in all of this is not the current melt but whether the winds this winter will disperse ice the same way they apparently did last winter. My understanding is that there was an unusually large amount of older ice flushed into the Atlantic last winter by anomalous wind patterns.

813. John Lang
Posted Aug 24, 2008 at 9:42 AM | Permalink

To David #813 – Red is snow and ice. Whites and Pinkish-Orange are cloud cover.

Generally, the pinkish-orange signals cooler cloud tops so most of the time this is high cloud tops but fog also shows us in this color as well sometimes.

814. DeWitt Payne
Posted Aug 24, 2008 at 10:30 AM | Permalink

CT area update
region area(Mm2) difference anomaly
Arctic 3.62 -0.049 -1.796
Antarctic 14.357 0.003 -0.298

Projected minimum still 3.3 Mm2. Based on rate, 2008 is 4 to 5 days behind average which would put minimum area on about 9/10. Considering that the recent average minimum is about 4 Mm2, 2008 looks to be closer to 2007 than is comfortable. Average area will probably look better, as we aren’t seeing the deep flat bottom of 2007 yet. When and how fast area increases will be important. I expect the Antarctic to continue to fluctuate. It’s due for an uptick soon.

Clouds and fog are very dark gray bodies. They radiate according to the temperature at the cloud top. In winter with a temperature inversion, low clouds or fog could actually radiate more energy to space than would be the case with no clouds. OTOH, with a temperature inversion, there aren’t likely to be low clouds, I think.

815. DeWitt Payne
Posted Aug 24, 2008 at 10:54 AM | Permalink

Today’s downward revision in extent reduces the projected extent minimum to 5.06 Mm2 on 9/15 and 4.6 Mm2 on 9/25 by the remaining extent and rate methods.

816. bender
Posted Aug 24, 2008 at 10:59 AM | Permalink

It’s fine to put 2008 under the microscope to figure out what’s going on. But at the end of the day you need to put 2008 in proper context by comparing the projected final value for 2008 to the previous observed values. The best way to do this is a time-series graph, with the 2008 point plotted as a mean +/- prediction interval. Such a plot would make it clear that the season is more or less over as far as any informative signal that can be extracted: 2008 was a pretty big melt year. Whether the realized 2008 ends up being a tiny bit above or below 2007 is inconsequential relative to the measurement error and the stochastic process error.

817. Aaron Wells
Posted Aug 24, 2008 at 11:28 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. As other’s have pointed out, the revision this morning was a rather dramatic reduction in the area from last night. This is particularly significant when you consider that the change in the daily loss value, which went from around 40,000 km^2 to 55,000 km^2, an increase of around 35% from last night. Needless to say, the graphs from last night were more optimistic than the final for today.

Daily Arctic Sea Ice Extent Reduction Day 236

Arctic Sea Ice Extent Day 236

2008 Arctic Ice Extent Differences From Previous Years Day 236

2007 continues to fend off 2008 from passing it for total drop from peak!

Arctic Sea Ice Total Drops from Peaks Day 236

818. TAC
Posted Aug 24, 2008 at 9:11 PM | Permalink

Preliminary Unofficial Day 237 Race Report
2008 has big day, now about 590K behind 2007.
8 25 2002 6.102500 -0.014688
8 25 2003 6.418125 -0.030000
8 24 2004 6.127969 -0.007344
8 25 2005 5.852500 -0.000625
8 25 2006 6.031250 -0.012188
8 25 2007 4.847656 -0.027969
8 24 2008 5.435781 -0.064375

819. BarryW
Posted Aug 24, 2008 at 9:26 PM | Permalink

2008 is now only 0.120625 above 2005’s minimum. Two more days like this…

820. Posted Aug 24, 2008 at 9:42 PM | Permalink

BarryW:
August 24th, 2008 at 9:26 pm
2008 is now only 0.120625 above 2005’s minimum. Two more days like this…

In area it has been below all years except for 2007 for sometime now and is currently ~0.5 Mm^2 lower.

821. Aaron Wells
Posted Aug 24, 2008 at 9:56 PM | Permalink

In area it has been below all years except for 2007 for sometime now and is currently ~0.5 Mm^2 lower.

“and is currently ~0.5 Mm^2 lower.”

Lower than what? Not 2007. 2008 ice area is still about 600,000 km^2 above 2007. What year are you referring to?

822. Aaron Wells
Posted Aug 24, 2008 at 10:04 PM | Permalink

8 24 2008 5.435781 -0.064375

This was a rather big loss of extent area. Looking at CT’s ice concentration maps between yesterday and today, I don’t see how they came up with such a big reduction. Comparing them, they look nearly identical. A little bit of loss in the Beaufort Sea area, but that’s pretty much the only difference. Maybe they will revise a significant amount upward tomorrow.

CT Comparison 8/23 vs 8/24

823. Posted Aug 24, 2008 at 10:08 PM | Permalink

Re #823

Lower than what? Not 2007. 2008 ice area is still about 600,000 km^2 above 2007. What year are you referring to?

All of those before 2007 as the preceding clause should have made clear: ‘In area it has been below all years except for 2007

It’s not just the ‘baby ice’ either, this graph of thickness for some ice in the fragmented ice N of the Beaufort Sea shows that multiyear ice is going too.

824. DeWitt Payne
Posted Aug 24, 2008 at 10:08 PM | Permalink

I’m not at all sure it is over for 2008. I should have plotted the data this way before. On the same day as today in 2007 the projected minimum was 4.81 Mm2 compared to 5.01 Mm2 today. The smoothed loss rate for 2008 is almost 0.02 Mm2 higher than 2007 at present. I can no longer say with confidence that 2007 is out of reach. It will depend very much on what happens each day for the next three to four weeks.

825. DeWitt Payne
Posted Aug 24, 2008 at 10:21 PM | Permalink

As the character on SNL used to say: “Never mind.” I stupidly plotted the upper limit column for 2007. The 2007 minimum is safe. Here’s the revised graph showing that 2005 and 2006 are also out of reach

826. DeWitt Payne
Posted Aug 24, 2008 at 10:47 PM | Permalink

WWF is now running a spot on polar bears called “On Thin Ice” (the video is on this page)to drum up members. It seems more than a little over the top to me but is somewhat on topic for this thread.

827. bender
Posted Aug 24, 2008 at 10:47 PM | Permalink

That 2008 is closing the gap on 2007 this fast this late in the season is somewhat impressive, don’t you think? Without knowing precisely how much is the result of win vs. temperature vs. the positive feedbacks (open water=lower albedo) incurred from the June melt (esp. high in 2007), I don’t think I would bet the house on 2007 being safe. I would be a lot more comfortable with a process-driven model of daily melt than I am with these black box forecasting methods. This gets back to what Phil was arguing earlier about the old caveat “all things being equal”. If arctic climate is non-stationary then the past is not as strong an indicator of the future as you might think.

An LTP trend model would suggest that whatever happened last year could continue this year. Especially if you think Arctic Ocean circulation is an LTP source. As it stands all these models are assuming years are independent of one another.

828. Posted Aug 24, 2008 at 11:10 PM | Permalink

Re #828

DeWitt Payne:
August 24th, 2008 at 10:47 pm
WWF is now running a spot on polar bears called “On Thin Ice” (the video is on this page)to drum up members. It seems more than a little over the top to me but is somewhat on topic for this thread.

Although reports like those from the yacht Berrimilla which recently sailed through the NW Passage concerning a Polar bear and cubs swimming 50 miles off shore do make you wonder what effect a prolonged series of summers like this will have on them?

829. Jon
Posted Aug 24, 2008 at 11:11 PM | Permalink

That 2008 is closing the gap on 2007

Yes quite so. Now the question is: when will the minimum be. There is about a 50 day range. The higher order derivatives take on large values historically, so the changeover will be sudden and therefore surprising.

830. Posted Aug 24, 2008 at 11:29 PM | Permalink

Re #829

An LTP trend model would suggest that whatever happened last year could continue this year. Especially if you think Arctic Ocean circulation is an LTP source. As it stands all these models are assuming years are independent of one another.

Here’s a plot of the sea ice area minima since ’78, there’s a persistent downward trend over time but considerable y-to-y variation, 2008 & 2007 are off scale of course.

831. Raven
Posted Aug 25, 2008 at 12:02 AM | Permalink

Phil,

Bender’s LTP speculations aside I will have to concede that the warmers were right on the sea ice melt predictions even if it does not quite reach the 2007 levels. OTOH, I never disputed that the planet is warming and the loss of the NH ice would be a consequence no matter what the cause. It is too bad that we don’t have satellite ice data from 40s – I would really like to know the how different today is from the last time ships could navigate the NWP.

832. Posted Aug 25, 2008 at 12:35 AM | Permalink

Re #833

It is too bad that we don’t have satellite ice data from 40s – I would really like to know the how different today is from the last time ships could navigate the NWP.

I’d say it was quite a bit different, for a start St Roch took 28 months to cross from W-E including over-wintering in the ice on the Boothia peninsula for 2 winters, the same route that Berrimilla, a 33′ fiberglass yacht, took this summer AC-AC in a month. The St Roch did the reverse journey in 86 days via the more northerly route, a route that has been wide open last and this, Polarstern just traversed the passage in 4 days. Seven yachts have traversed the Amundsen route this summer, it’s still dangerous but a shadow of what it was in the 40s.

833. Raven
Posted Aug 25, 2008 at 12:52 AM | Permalink

#834 – All of the boats going through the passage now have he benefit of satellite technology and could plan their trips knowing it was largely ice free. In 1940s the St. Roch had to make a bet that the passage would be open an could have guessed wrong even if the passage was open earlier or later in the season. More importantly, the St Roch completed the return trip in 1944 through open water in 86 days (from Vancouver to Halifax) – a pretty fast pace for a ship of that vintage.

That said, I suspect the current meltback is larger but I am not convinced that it is that much larger. Unfortanately, we don’t have the data that would settle this question conclusively.

834. Chris
Posted Aug 25, 2008 at 12:54 AM | Permalink

Don’t read too much into one day. Especially as it seems to been caused by a low pressure system bringing a cold plunge to areas previously anomalously warm. Just wait a couple of days for the ice to adjust…..

Think about the following figures from 2003:
– Average extent reduction 24th-31st August: -0.024
– Extent reduction 1st Sep: -0.064 (i.e. exactly the same as today)
– Average extent reduction 1st-8th September: -0.016

I’ve been hopeful for 2008 to slow down more quickly than it has because I would like to see an even stronger recovery from 2007. But from the way weather conditions have developed recently in the Arctic, whatever happens in the next few weeks, 2008 is going to show a small but significant recovery.

I’m getting tired of trying to counter over-pessimism from warmists and skeptics alike! You’ve just got to look at the big picture. Like with the buoys. How about the ones that Phil doesn’t link to? yes of course there’s one or two on the edge of the Beaufort sea that show dramatic thickness reduction because last year they were on the edge of the ice but now are open water.

But what about this one just north of the Canadian Archipelago? Was ~ 3m thick this time last year, now ~3.5m thick? http://www.crrel.usace.army.mil/sid/IMB/2007J.htm

Or this one? Very close to the one Phil linked to, but slightly into the Arctic Basin from the Beaufort sea, well over 3m thick despite southward drift? http://www.crrel.usace.army.mil/sid/IMB/2008F.htm

Or this one closer to the north pole, > 2.5m thick? http://www.crrel.usace.army.mil/sid/IMB/2008C.htm

Yet everyone’s been going on about that NASA survey last year showing the ice only 1.5m thick, and assuming that it can only have got thinner this year.

I know what it’s like to over-reach yourself with predictions – I’ve done it on this thread! And I suspect that’s what many have been doing with predicting the demise of the Arctic ice. We’ll see what the next winter and summer bring. Myself, the big picture makes me optimistic.

Because 2008 is looking almost certainly to end up a kind of half-way house between 2007 and previous years, it’s not going to be evidence either way for warmists or skeptics – it’s going to be a matter of viewpoint as ever. (Except that it’s DEFINITELY defied the more alarmist predictions which are what got me interested in Arctic ice this summer in the first place) That’s why I’m starting to lose interest in the finer details of the last couple of weeks of melt.

What interests me far more at the moment is the uptick in the SOI, and associated beginnings of ocean cooling west of equatorial S America. It’s too short term to mean anything at the moment, but this will probably be what I’ll be most interested in the next couple of months now that the ice issue has practically run its course for the time being. The 30-day SOI has just reached a similar level to the peaks of the last couple of months, and it looks like in the next couple of days it will reach its highest level since April, close to +5 (~La Nina threshold, if sustained). I’m not saying I think this will continue (some experts have predicted El Nino), I just think it will be very interesting to see what happens in the southern oceans in the next few months.

835. AndyW
Posted Aug 25, 2008 at 1:19 AM | Permalink

Very much surprised by another 60k day and the revision downwards over coffee this morning.My 5.0Mm extentminima is now looking pessimistic. I’m not changing down to 4.0Mm though :)

It will be interesting to see what the maxima will be in Q1 2009 and what effect that has on 2009 season. I would hope we are not on the same thread and 5000 posts by then though, it takes a while to load up. Maybe go to the forum?

Regards

Andy

836. Aaron Wells
Posted Aug 25, 2008 at 8:33 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data. The morning revision went in the opposite direction than I expected, given that the preliminary value was rather extreme, especially when the ice concentration maps are viewed side-by-side for the 23rd and the 24th. Rather than revising the area upwards, they had a fairly extreme downward revision, around 9,000 km^2, to boost the day’s reduction from around 64,000 km^2 to around 73,000 km^2. In fact, the revision was more on the order of the average (’02 – ’07) total extent area reduction for day 237 (~15,000 km^2).

Daily Arctic Sea Ice Extent Reduction Day 237

Arctic Sea Ice Extent Day 237

2008 Arctic Ice Extent Differences From Previous Years Day 237

2007 continues to fend off 2008 from passing it for total drop from peak, although by the slimmest of margins (7,969 km^2).

Arctic Sea Ice Total Drops from Peaks Day 237

837. Posted Aug 25, 2008 at 9:16 AM | Permalink

Re #835

#834 – All of the boats going through the passage now have he benefit of satellite technology and could plan their trips knowing it was largely ice free. In 1940s the St. Roch had to make a bet that the passage would be open an could have guessed wrong even if the passage was open earlier or later in the season.

While the sat links and ice maps obviously make things easier the decisions are still far from simple, Berrimilla left Nome well before it was clear that the passage would open at all and the route was still blocked solid at that time. Remember St Roch was reinforced to survive being frozen in ice, Berrimilla is not.
As it happened it worked out but there were no guarantees, the stretch N of Gjoa Havn was rather hairy.
When starting out from Aus. in April of course they had no more information available than the St Roch did in 1940.

838. Posted Aug 25, 2008 at 10:26 AM | Permalink

Bateaux connus ayant tenté (fait la partie la plus incertaine du passage : le verrou de glaces de LARSEN SOUND au 15 août 2008)

AMODINO – ARCTIC WANDERER – BALOUM GWEN – BERRIMILLA – GERALDINE – SOUTHERN STAR – TY HINA

Known boats having crossed Northwest Passage

839. DeWitt Payne
Posted Aug 25, 2008 at 11:19 AM | Permalink

CT ice area update 8/24/2008
region area(Mm2) difference anomaly
Arctic 3.605 -0.015 -1.802
Antarctic 14.35 -0.007 -0.3

Projected minimum area still 3.3 using current concentration and projected extent as well as current smoothed rate and U.Hamburg average rate to calculate days until minimum area, which is now 9/11/2008.

I’m really more interested in the average extent and area for the full year. Right now it looks as if 2008 could have higher average extent than 2006 and 2005. So I’ll continue to keep following this long after this year’s minimums are reached.

840. AndyW
Posted Aug 25, 2008 at 11:25 AM | Permalink

At the end of the 2008 melt season and when people are jostling to and fro on what it all meant I think Aaron’s total drop from peak might be worth a few bob for the AGW crowd and Aaron should start charging \$10 a pop for quoting it.

It might be the most important graph of the season and maybe no AGW person will know about it to use in discussions!

Regards
Andy

841. Posted Aug 25, 2008 at 11:48 AM | Permalink

Re #842

At the end of the 2008 melt season and when people are jostling to and fro on what it all meant I think Aaron’s total drop from peak might be worth a few bob for the AGW crowd and Aaron should start charging \$10 a pop for quoting it.

Do you think I should ask for a piece of that action (see here)? ;)

842. BarryW
Posted Aug 25, 2008 at 11:57 AM | Permalink

Here’s a graph of another way to look at the extent loss. It’s the extent loss expressed as a percentage per day of the extent that’s left. 2008 is running at almost twice the average.

843. Aaron Wells
Posted Aug 25, 2008 at 12:05 PM | Permalink

At the end of the 2008 melt season and when people are jostling to and fro on what it all meant I think Aaron’s total drop from peak might be worth a few bob for the AGW crowd and Aaron should start charging \$10 a pop for quoting it.

It might be the most important graph of the season and maybe no AGW person will know about it to use in discussions!

Regards
Andy

I’ll take pay-pal! ;-)

Trust me, I don’t include it as fodder for AGW argument. I actually posted it once as a special addition because I had been tracking it with my spreadsheet and it originally appeared unlikely for 2008 to catch up with 2007 drop from peak. I did not have plans to post it regularly, but when it appeared likely at one point that it was going to cross the 2007 curve, I felt an obligation to post the graph again, since Phil had often brought up the issue of drop from peak, instead of just tracking the minimums. I subsequently found a problem with my spreadsheet which, when corrected, resulted in 2008 not quite approaching 2007 in drop from peak.

It now seems likely that 2008 will match or exceed (but probably not by much) the drop from peak that occurred in 2007. It is what it is. I personally don’t think that it means much, because I am not sure that starting out had a higher maximum necessarily affects the minimums. What we see in the graphs of all of the past 6 years extent curves, is that regardless of what the maximums were, they all converge during late-April (day 111) to early-June (day 176) to a much tighter range. See
graph. It seems irrelevant to me what occurred prior to the point where they are much tighter, since they eventually come to nearly the same extent during the Spring. To me, it is much more relevant what happens after the “tight” (convergent) point in the curves. Notice that the same tightening generally occurs during freeze phase as well.

844. Shawn Whelan
Posted Aug 25, 2008 at 12:08 PM | Permalink

It is not likely Larsen could have taken the St. Roch through the northern passage this year. Certainly he could not have followed the route of 1944. The trip is well documented and Larsen wrote the book, “The Big Ship”. Less ice in 1944 than 2008? It appears so.

http://www.ucalgary.ca/arcticexpedition/larsenexpeditions

845. bender
Posted Aug 25, 2008 at 12:40 PM | Permalink

Naturally, the alarmists want you to talk about sea ice because the issue here are the fairly powerful knock-on (+) feedback effects of GHGs in the arctic. What they OUGHT to be discussing are main GHG effects as inferred from GCMs. Coolers who prefer to talk about sea ice over GCM uncertainties are committing agendicide.

mosher has made this point in the past and he’s right.

846. Posted Aug 25, 2008 at 12:57 PM | Permalink

Re #846

Shawn Whelan:
August 25th, 2008 at 12:08 pm
It is not likely Larsen could have taken the St. Roch through the northern passage this year. Certainly he could not have followed the route of 1944.

I think he would have got through just fine, the route is mostly open water with a few patches of 1-3/10 ice. He wouldn’t need to follow the exact route because he could go straight out through McClure rather than down Prince of Wales Strait.

The trip is well documented and Larsen wrote the book, “The Big Ship”. Less ice in 1944 than 2008? It appears so.

I disagree, Larsen was forced to go along the lead right on the mainland coast and only just made it, this year there’s a hundred mile wide stretch of open water there (no ice in the Beaufort south of 75ºN)!
Traveling west along the coast of Alaska, the St. Roch found itself in a battle against the ice as it tried to reach Bering Strait before it was locked in for the winter.

847. DaveM
Posted Aug 25, 2008 at 2:47 PM | Permalink

Forgive me but I am going from memory here… (I grew up two blocks from the Vancouver Maritime museum. I spent many a day scrambling all over the Roch: prior to it being restored to any meaningful degree). If I recall the tale correctly, didn’t the St. Roch leave late for some reason? I have a feeling they went in several weeks later than planned.

848. Shawn Whelan
Posted Aug 25, 2008 at 2:53 PM | Permalink

The St. Roch had clear sailing through the NW passage and the route Larsen took is blocked and impassable in 2008. I don’t believe the Northern Northwest Passage is open except to icebreakers. No matter it isa fact that many decades ago the Arctic had a clear route through the Northern Passage that is closed in 2008. Obviously this is not the first time for such low ice levels.

http://www.ucalgary.ca/arcticexpedition/larsenexpeditions

849. Shawn Whelan
Posted Aug 25, 2008 at 2:56 PM | Permalink

Larsen probably would have made it through in 1940 except for a late start.

“He had intended on the west to east transit to take the route through the uncharted Prince of Wales Strait but they were diverted back from Holman Island to the mainland (Tuktoyaktuk). On their return the Prince of Wales strait was ice packed and Larsen, hoping to still get out that year, decided to follow Amundsens shallow route.”

http://lit.lib.ru/t/tatarin_l_s/msword-29.shtml

850. DeWitt Payne
Posted Aug 25, 2008 at 2:59 PM | Permalink

Coolers who prefer to talk about sea ice over GCM uncertainties are committing agendicide.

I have to disagree. I think the warmers are correct that sea ice is a sensitive indicator of global heat content. However, I don’t think this is necessarily favorable for them. Direct ghg forcing at high latitudes is small. Do I need to post the GISS plot again? I don’t have the numbers for the 1979 to present trend in the global sea ice anomaly, but the eyeball says not very much if any. In the Arctic, the question is whether this is a replay of the 1910 to 1940 warming and will be followed by cooling at high North latitude and increased ice or whether the current trend will continue. One year’s ice area or extent annual range is too noisy to really tell much. The annual average is a much better measure. The Year to Date average extent for 2008 is lower than the YTD averages for 2007, 2006 and 2005, as would be expected from the MSU 60 to 82 N latitude exponentially smoothed anomaly, which appears to be correlated to ice area. The p value of the slope is 3E-08 and the 95% confidence limits are -0.073 to -0.043.

851. BarryW
Posted Aug 25, 2008 at 4:06 PM | Permalink

It appears that the earth is developing a heat differential N/S link and seems to be larger as you near the poles. Is there any model or known trend that can explain this? If CO2 is “well mixed” then wouldn’t you expect the SH to show similar warming?

I tried to post this earlier, another eaten link

This is a graph of the smoothed percentage of extent lost relative to the extent for that day.

Percentage graph

It appears that the present rate is about twice that of the average.

Posted Aug 25, 2008 at 4:44 PM | Permalink

Within one week, we’ll know.

Posted Aug 25, 2008 at 4:51 PM | Permalink

FZAK80 PAFC 251835 AAA
ICEAFC

1035 AM AKDT MONDAY AUGUST 25 2008

FORECAST VALID…SATURDAY AUGUST 30 2008

ANALYSIS CONFIDENCE…LOW-MODERATE

SYNOPSIS…A LOW PRESSURE CENTER EAST OF WRANGEL ISLAND WILL REMAIN
RELATIVELY STATIONARY THROUGH THURSDAY AND THEN SLOWLY WEAKEN AS IT
MOVES NORTH OF WRANGEL ISLAND ON FRIDAY AND SATURDAY.

-ARCTIC OCEAN-
-BEAUFORT SEA-
-CHUKCHI SEA-

PKZ225-CAPE THOMPSON TO CAPE BEAUFORT-
PKZ230-CAPE BEAUFORT TO POINT FRANKLIN-
PKZ235-POINT FRANKLIN TO CAPE HALKETT-
PKZ240-CAPE HALKETT TO FLAXMAN ISLAND-
PKZ245-FLAXMAN ISLAND TO DEMARCATION POINT-

THE MAIN ICE EDGE LIES FROM 72.4N 158W TO 71.6N 160W TO 71N 163W TO
71.2N 167W TO 72.3N 170.5W TO 72.3N 178W AND SOUTHWEST TO WRANGEL
ISLAND. THE EDGE IS MAINLY 3 TO 7 TENTHS FIRST YEAR THIN
ICE…YOUNG…NEW.

FORECAST THROUGH SATURDAY…
FOR THE LOBE OF ICE CENTERED NORTHWEST OF PT. BARROW…EXPECT
TEMPERATURES IN THE MID TO UPPER 20S WITH SOME WEST WINDS THROUGH
TUESDAY. EXPECTING 20 TO 30 NM SOUTHEASTWARD MOVEMENT OF THE EDGE BY
TUESDAY BUT A RETREAT BACK TO THE CURRENT POSITION BY SATURDAY.

WITH AIR TEMPERATURES IN THE MID 20S THIS WEEK EXPECT SOME NEW ICE
FORMATION IN AREAS NORTH OF 72.5N AND WEST OF 160W.

JMP JULY 2008

\$\$


854. Shawn Whelan
Posted Aug 25, 2008 at 7:30 PM | Permalink

Resolute temps 2007 compare to 2008

http://www.climate.weatheroffice.ec.gc.ca/climateData/hourlydata_e.html

The Canadian Arctic is mostly much colder in 2008 compared to 2007.

855. Posted Aug 25, 2008 at 8:09 PM | Permalink

Re #855

THE MAIN ICE EDGE LIES FROM 72.4N 158W TO 71.6N 160W TO 71N 163W TO
71.2N 167W TO 72.3N 170.5W TO 72.3N 178W AND SOUTHWEST TO WRANGEL
ISLAND. THE EDGE IS MAINLY 3 TO 7 TENTHS FIRST YEAR THIN
ICE…YOUNG…NEW.

Describing it as ‘the main ice edge’ seems like overkill:

856. TAC
Posted Aug 25, 2008 at 9:07 PM | Permalink

Preliminary Unofficial Day 238 Race Report
2008 has a WHOPPER day, now about 500K behind 2007.
8 26 2002 6.039219 -0.063281
8 26 2003 6.387344 -0.030781
8 25 2004 6.114531 -0.013438
8 26 2005 5.829688 -0.022812
8 26 2006 5.993750 -0.037500
8 26 2007 4.818438 -0.029218
8 25 2008 5.318594 -0.108281

857. DeWitt Payne
Posted Aug 25, 2008 at 9:59 PM | Permalink

The rate method puts the minimum date in early October at 4.1 Mm2. I don’t think a minimum date that late is possible. The area method projects 4.91 Mm2 on 9/16. I don’t believe that either because it’s dropping too fast. Smoothed loss rate is now higher than any previous year at this time, although not by much -0.06682 in 2004 and -0.712 today. However, at this point in 2004 the loss rate was dropping rapidly heading for a minimum extent on 9/11/2004. No such luck in 2008. It’s looking like it will take a serious break in the weather for the minimum to be reached before last year’s date of 9/24. I’m not quite ready to put baby ice extent on the critical list, but a few more days of 50,000+ km2/day loss will do it.

858. Posted Aug 25, 2008 at 11:34 PM | Permalink

Re #850

Shawn Whelan:
August 25th, 2008 at 2:53 pm
The St. Roch had clear sailing through the NW passage and the route Larsen took is blocked and impassable in 2008. I don’t believe the Northern Northwest Passage is open except to icebreakers. No matter it isa fact that many decades ago the Arctic had a clear route through the Northern Passage that is closed in 2008. Obviously this is not the first time for such low ice levels.

The Northern Passage is far from closed, sure the Polarstern just passed through in three days but that doesn’t mean that you have to have an icebreaker to get through! current ice
Eastern end.
The St Roch would certainly be able to get through this if the accounts of what she went through in Bellot Strait are right.
“By August 1942 they had to chance an escape. Their supplies were low and there was no game in the area. On Aug 4 they moved out of Paisley Bay but were locked in, drifting back and forth for 20 days. Then on Aug 24 they got a small lead. By August 29 they were adjacent to Bellot Strait, a passage 18 mi long and Ґ -1 mi wide between Peel Strait and Prince Regent Inlet. They got to the middle but were locked in with solid ice ahead, and behind the ice came in like a maelstrom. Three times they prepared to abandon ship, though one of the crew (Hadley) later said he didnt know where they would go, the cliffs are high. Another ( Farrar) described seeing a huge whale crushed to death by the ice right near them. Larsen said that if they hadnt got through they would have been there yet.”
This is what that area looks like today, Bellot St is the narrow passage nth of the little square island halfway up on the east side, Larsen described the ice conditions of 40-42 as the worst of his career in the arctic.

859. AndyW
Posted Aug 26, 2008 at 12:36 AM | Permalink

Surprising ice loss amount yesterday, if it doesn’t get adjusted down ( and they seem to be adjusting up at the moment ) then I think it will be the latest 100K on the spreadsheet by a long way. I’ll be interesing to see Aaron’s graph after this.

I am about to go on holiday to Portugal where the only ice I will be watching will be some floating in alcoholic beverages. I’m going to me miss my daily CSV download :(

Regards

Andy

860. Chris
Posted Aug 26, 2008 at 12:49 AM | Permalink

8 25 2008 5.318594 -0.108281

Ouch that hurt :( I would now say that it’s *extremely* unlikely that 2008 will fail to beat 2005’s record!! (5.315 on 22nd Sep)

Over-optimism with extent was never a good idea what with all the ice cut off from the main ice pack, in the Chukchi/East Siberian/Laptev seas. The first winter storm and the floes are just dispersing rapidly into <15% concentration, even if melt in those areas has probably slowed. (While re-freeze has of course started in the Arctic Basin)

I’m just going to settle for assuming that 2008 extent will end up roughly halfway between 2007 and 2005, i.e. a significant recovery but not as much as I’d hoped, and leaving room to be pleasantly surprised (as opposed to crushingly disappointed like today!)

861. AndyW
Posted Aug 26, 2008 at 12:50 AM | Permalink

There is an update at NSIDC as well

http://nsidc.org/arcticseaicenews/

“Based on NASA Advanced Microwave Scanning Radiometer—Earth Observing System (AMSR-E) satellite images from the University of Bremen the wider, deeper Northwest Passage through the Parry Channel is almost open. The United States National Ice Center confirms that Amundsen’s Northwest Passage is navigable. The AMSR-E data furthermore indicate that the Northern Sea Route (also called the Northeast Passage) is open. ”

Regards

Andy

862. Posted Aug 26, 2008 at 1:07 AM | Permalink

Based on NASA Advanced Microwave Scanning Radiometer—Earth Observing System (AMSR-E) satellite images

It’s JAXA not NASA!

863. Chris
Posted Aug 26, 2008 at 1:31 AM | Permalink

Is there a thread re: ENSO? It’s taken a lurch back towards La Nina in the last few days. 30-day SOI is now 4.51 and rising sharply, and 90-day SOI is now up to 2.83 (from ~0 during the first half of the month). Surface temperature anomalies west of equatorial S America, while still significantly positive, have taken a dive in the last few days (of ~0.5C with the last few days, up to ~1.5C within last week or so), and patches of cold upwelling have appeared all round the main “plume” of warmer waters. Looking at the pressure forecasts for Tahiti and Darwin, daily SOI values look set to continue high for the next week, taking the eventual August average well above +5.
Re: the Arctic ice, El Nino last winter seems to have helped bring about the big re-freeze which meant it was only anomalously warm winds in the “right” place in August that allowed 2008 summer melt to approach that of 2007. Another El Nino this winter and a 2009 recovery could stick.
(N.b. PDO “cool phase” tends to be associated with more/stronger La Ninas and less/weaker El Ninos)

http://weather.unisys.com/archive/sst/sst_anom-080817.gif [SST anomalies 16th Aug]
http://weather.unisys.com/archive/sst/sst_anom-080824.gif [SST anomalies 22nd Aug]
http://weather.unisys.com/surface/sst_anom.html [current SST anomalies]
http://www.bbc.co.uk/weather/5day.shtml?world=3076 [Tahiti pressure forecast]
http://www.bbc.co.uk/weather/5day.shtml?world=0097 [Darwin pressure forcast]

864. Chris
Posted Aug 26, 2008 at 1:35 AM | Permalink

Don’t believe it I said “El Nino last winter” – must be losing it. Oh **** I just noticed I said “Another El Nino this winter”.
I meant to say “La Nina” both times just in case it’s not obvious…….

865. crosspatch
Posted Aug 26, 2008 at 2:05 AM | Permalink

2008 started with a smaller amount of “old ice” so it doesn’t take as much heat to melt the 2008 ice as it took to melt 2007 ice. So even if 2008 ends up at the same point as 2007 did, it would have taken less heat to melt the ice in 2008 than it did in 2007 because it was thinner and it had a higher salt content. Given a repeat of 2007’s sunshine and wind conditions, 2008 would have, I believe, been a record low. That 2008’s ice has stood up this well so far says that conditions are much different this year. It is 2009 that will tell the story when we have more second year ice than we had in 2008.

866. Flanagan
Posted Aug 26, 2008 at 2:22 AM | Permalink

Actually I think the big loss was to be expected in view of the very large regions of very low concentrations which developed recently. Most of these having disappeared now, I suppose compaction will take over and that the melt rate will dimnish strongly – at least this is what I hope :0)
Has anyone any idea why the antarctic extent seems to be frozen (aha) to some very low values?

867. BarryW
Posted Aug 26, 2008 at 6:42 AM | Permalink

Re 862

I’ll bet 2008 is past 2005 this morning when they update since revisions lately seem get larger . All of the other years’ (2003-2007) extent loss rates are clustering together and 2008 is quite an outlier.

868. Posted Aug 26, 2008 at 8:17 AM | Permalink

Re #868

Actually I think the big loss was to be expected in view of the very large regions of very low concentrations which developed recently. Most of these having disappeared now, I suppose compaction will take over and that the melt rate will dimnish strongly – at least this is what I hope :0)

Compaction will still lead to reduced extent, melting had stopped by this time last year but extent continued to fall.

Has anyone any idea why the antarctic extent seems to be frozen (aha) to some very low values?

It’s not very low, it looks about normal for the time of year. Remember any new ice has to grow at 60ºS+ at a time when the day is lengthening and the sun getting higher in the sky.

869. AndyW
Posted Aug 26, 2008 at 8:48 AM | Permalink

The thing about the Antartic growth is that sooner or later it is going to hit the Southern Ocean cirumpolar storms which will blunt any further increase, especially as they seem to be getting stronger currently. Where as Artic snow could get down to zero there is a definite cap on the Antartic given no catastrophic happening.

Regards

Andy

870. Mike Bryant
Posted Aug 26, 2008 at 9:17 AM | Permalink

OMG!!! “Another ( Farrar) described seeing a huge whale crushed to death by the ice right near them.”

I had no idea that the sea ice was so violent. Save the whales! Get rid of that nasty sea ice…

871. flanagan
Posted Aug 26, 2008 at 9:17 AM | Permalink

Well, in fact I would like to take back what I said this morning… Has anyone given a look at the NSIDC “almost-real-time” extent values? It seems like they revised the morning figure to even greater losses (see here). Now, I don’t know if it’s going to be revised once more but rightnow it makes me wonder if 2007 will not simply be “underpassed” within a few days…

872. John Lang
Posted Aug 26, 2008 at 9:24 AM | Permalink

Yesterday’s Modis sat pics shows the northern route through the Northwest Passage is open – just one very small section of ice to get through.

873. Shawn Whelan
Posted Aug 26, 2008 at 9:45 AM | Permalink

Still not gonna go though the Northern NW Passage without an icebreaker capable boat. Much more ice in the passage than 1944.

874. BarryW
Posted Aug 26, 2008 at 10:14 AM | Permalink

And we have a winner, so to speak. 2008 has passed 2005’s extent minimum: 5.305313(2008) vs 5.315156 (2005).

875. Posted Aug 26, 2008 at 10:30 AM | Permalink

Re #875

You missed off your map from 1944, care to post it?

876. Shawn Whelan
Posted Aug 26, 2008 at 11:11 AM | Permalink

How about this one fill. Less ice in the Western Arctic in 1998 than 2007. Nothing new. The amount of ice has always varied.

Or the lowest ice in the NW Passage. Also 1998.

Basically just scare tactics to say the NW Passage has never been open before.

http://ice-glaces.ec.gc.ca/WsvPageDsp.cfm?Lang=eng&lnid=35&ScndLvl=no&ID=11886

877. Chris
Posted Aug 26, 2008 at 11:18 AM | Permalink

Note that SST anomalies are surprisingly tame in the Arctic at the moment. In the Chukchi seas, by this point:
– In 2005 anomalies were +5.5C http://weather.unisys.com/archive/sst/sst_anom-050828.gif
– In 2007 anomalies were +6.5C http://weather.unisys.com/archive/sst/sst_anom-070826.gif
– But in 2008 they are barely +4C http://weather.unisys.com/surface/sst_anom.html and starting to drop with the recent sub-zero temperatures/snow/northerly winds in the region http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/arcisoTTPPWW.gif
Because high SST anomalies are increasingly necessary for continued melt as you go into September, I would not bet on 2008 extent reduction continuing to be faster than either 2005 or 2007 for long. 2005 for example had even more low concentration ice around the fringes http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=25&fy=2005&sm=08&sd=25&sy=2008 . Furthermore, the remaining low concentration ice in 2008 (~40%) is now mostly on the Beaufort/Arctic fringe where it is particularly thick (~3m) and has been particularly resilient in recent weeks generally. Not to mention the cold temperatures there at the moment.
The low concentration ice in the East Siberian/Chukchi seas has practically gone now after the last couple of days! (Or more accurately, dispersed – note that the East Siberian sea is still cold enough to have a slice of zero anomaly SST in it, so melting will have been very slow) There remain a couple of ~60% concentration chunks, which will probably gradually disappear, but if they disperse this could offset any extent reduction in the short term (if they dispersed to ~30% without melting for example, then local extent could as much as double, other things being equal – I know this is an extreme case to illustrate the point)
The conditions in 2008 are unique (in recent years…), and therefore uniquely unpredictable. Anything could happen, so let’s just wait and see…..

878. Aaron Wells
Posted Aug 26, 2008 at 11:21 AM | Permalink

Here are my graphs for yesterday’s ice extent data, based upon IARC/JAXA Ice Extent data.

Daily Arctic Sea Ice Extent Reduction Day 238

Arctic Sea Ice Extent Day 238

2008 Arctic Ice Extent Differences From Previous Years Day 238

2008 crossed the 2007 total drop from peak curve in a big way today.

Arctic Sea Ice Total Drops from Peaks Day 238

Words fail me with this latest reduction data. It’s almost unbelievable. Percentage-wise, yesterday’s reduction was the largest single day reduction of any year for the past 7 years, amounting to a reduction of 2.24% of the extent area that existed the previous day. Given that this reduction was extraordinary, one would think that this fact would be painfully obvious in a visual examination. But I can’t see it. Can anyone else?

Yesterday compared to day-before-yesterday

879. Chris
Posted Aug 26, 2008 at 11:35 AM | Permalink

#880 Actually yes I see it! The 24th shows substantial areas of ice at ~20% concentration on the Chukchi/Arctic Basin fringe (it’s rare to see much of this “turquoise” colour from what I recall of previous maps), but by the 25th they’ve vanished. It looks like they’ve been dispersed by the recent storm. Ice extent is of course defined as areas with >15% ice concentration, so it may be the ice is mostly still there but spread out at say 10% concentration. I would love it if it blew back and the ice extent “bounced”! but i’m taking a break from too much optimism after today’s result…….

880. MrPete
Posted Aug 26, 2008 at 11:45 AM | Permalink

Even more amazing to me in that one-day-change visual: a huge area went from ~100% to ~70% coverage. In a single day.

881. DeWitt Payne
Posted Aug 26, 2008 at 11:45 AM | Permalink

CT area update 8/25/2008
region area(Mm2) difference anomaly
Arctic 3.579 -0.026 -1.829
Antarctic 14.306 -0.044 -0.34

Arctic ice concentration has increased to 67.5% from its low of 63.4% on 8/18. Looking at the data from 2002 to 2006, the average concentration doesn’t go below about 73%. Projected minimum area is still about 3.3 Mm2. U.Hamburg minimum area for 2007 was 3.25 Mm2 on 9/15. I only have three days overlap on CT and U.Hamburg area data which has U.Hamburg about 3% higher than CT. Considering they’re using different satellites, that’s not bad.

882. Aaron Wells
Posted Aug 26, 2008 at 12:02 PM | Permalink

The 24th shows substantial areas of ice at ~20% concentration on the Chukchi/Arctic Basin fringe

Chris, that’s not what I would call substantial. Nowhere near 2.24% of the total area (my opinion).

883. AndyW
Posted Aug 26