Looking at the Ward Hunt Ice Shelf, the specialist literature distinguished between “basement” ice that is relatively old and firn ice that is much younger. The “basement ice” period ended with the end of the “first ablation period” which Crary 1960 dated to ~1600 BP – a date which Lyons et al 1973 noted to reset uncomfortably with dates from Greenland ice core. “Basement ice” is marked by an angular unconformity with more recent ice and by a heavy dirt layer, which is the residue of many years of ablation. Some portions of the ice shelf were confidently dated as being relatively young by virtue of the absence of the dirt layer. Some recent ice shelf calving e.g. the large 1961-1962 break at Ward Hunt ice shelf or the small 2003 break at Ward Hunt ice shelf almost certainly do not contain any “basement ice”. The Hobson’s Choice ice island (discussed in Jeffries 2002) did not have any basement ice. At present, I don’t have information on calving from Ayles ice shelf.
Today I’d like to discuss the evidence from ice island T-3, which was a prominent feature of early exploration in this area, because it was the location of an exploration camp. Jeffries 2002 (an interesting survey) reported that ice islands were discovered by reconnaissance flights following World War II and were quickly attributed as being calved from the Ellesemere Ice Shelf. Jeffries 2002:
The first ice island, named T-1, was seen in 1946, when a U.S. Army Air Force (USAAF) reconnaissance mission over the Arctic Ocean reported a heart-shaped ice mass that had dimensions of 24-29 km and an area of about 500 km surrounded by sea ice (Koenig and others, 1952). Subsequently, ice islands T-2, T-3, T-4, and T-5 were observed from the air or identified on aerial photographs between 1946 and 1950 in the Arctic Ocean, and 59 unnamed ice islands were found in aerial photographs of the Canadian Arctic Archipelago taken in 1950 (Koenig and others, 1952).
Some interesting historical information on the scientific camp can be seen if you google “t3 ice island”.
The T3 ice island proved to have a very distinctive dirt layer – similar to the dirt layer in Ward Hunt basement ice. Crary 1960 radiocarbon-dated the dirt layer obtaining dates exceeding 3000 BP and hypothesized that it was older than the Ward Hunt ice shelf as follows:
T3 may be older than the ice shelf at the Ward Hunt island area. The outcropping of a heavy dirt layer on the edges of T3 was 10 to 15 meters higher than its location at the camp site on T3; the steep dip of the ice layers south of the Ward Hunt ice rise (Marshall 1955) are best explained by a rising of the land areas. The old strand cracks found at an elevation of more than 20 meters above the present active ones on the south side of the Ward Hunt ice rise are difficult to explain except by uplift of land. Using C14 ages of the marine shell samples, which give an uplift of about 0.5 meters per centurry, a minimum age of a few thousand years could be expected for both the ice island and ice shelf.
Crary and others attributed the origin of the T3 ice island to an earlier break-up of the ice shelf at Cape Yattersley – presumably taking place at some point subsequent to the Peary expedition in the 1890s, perhaps the warm 1930s.
The interesting aspect for interpretation of this class of evidence is that T3 is an attestation of the break-up of basement ice in the 1930s. Over 90% of the Ellesmere ice shelf is said to have already taken place. I am unaware of any evidence of recent break-up of basement ice at Ward Hunt ice shelf and the maps indicate that the basement ice has remained intact. Even if the Ayles calving includes basement ice (which cannot be discerned one way or the other from the information that I’ve seen), calving (of basement ice) seems to have been much more prevalent in earlier parts of the 20th century, suggesting that recent warming is not necessarily critical in whatever is going on.
Climate Audit 
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You all have no doubt read that we are experiencing “the lowest Arctic Ice extent everrrrrrrrrr recorded.” (….. according to NSIDC, past data adjusted, based solely on non vicible band image collection via satellite, etc, etc, etc.) What they are not talking about is how the Arctic ice has been squeezing down against Greenland and pushing into the Atlantic, where of course, it then melts. The push is due to winds. Those same winds have been pushing the ice northward in the neighborhood of the International Date Line. Also, to those imagining that the Northwest Passage is open, sorry the break the news, there is still no clean path through the Canadian Archepelego, no way to get from the NWT shores to the Davis Strait. If it does not open up over the next couple of weeks, it won’t this year.
Here is good picture from the Terra/Modis satellite from a few hours ago.
This one is false color with sea ice colored Red (Note: the Orange color is cloud-cover).
Meanwhile, NSIDC and Cryosphere today show the ice edge about 400 miles north of Barrow. Completely wrong. On that note, here is an interesting slide deck:
The truth about so called passive microwave “sea ice extent measurements”
Enjoy!
Re #3 Slide 11 is a jaw-dropper.
Another oddity is the sudden 0.75MM km2 drop in Arctic ice extent in late 1978 just as satellite estimates were introduced.
The paper I want to find is, “Estimating Arctic Sea Ice Extent: Details on the Changes in Measurement Devices and Algorithms over Recent Decades and How They Were Grafted Together”.
Think you are referring to slide 6 on the Arctic ice extent drop. Definitely has to be a major question mark but 1978-79 was an unusually harsh winter from what I remember.
I explained poorly. Slide 11 discusses the summertime problems with passive microwave measurements, which underestimates summer ice extent by around 25%.
My problem is that, as technology advanced, there were changes in both measurement devices and in the ways the data was processed. Strengths and weaknesses varied, as with the passive microwave approach. So how does one compare say the published 1954 or 1997 ice extent numbers with 2007?
Indeed, this has many of the same issues as the Hockey Stick. Grafting, different error bars during different periods and different sources of error during them. Based on nearly daily observations of about 2 years worth of various representations of extent, based on “processed” passive microwave data, I have personally lost all faith in this particular method. It’s a box canyon. A big mistake was made when the cryological science community committed massive funds to this method. Now there is momentum and we are essentially stuck with it for at least another 10 years. What a shame.
I’ll be interested to see if Gavin responds to the following, assuming the censors allow it in, posted on the thread that is “lowesssstttt sea ice extent since the Pleistocennnnnne,” in all but name, over at RC:
263. SteveSadlov Says: Your comment is awaiting moderation.
27 August 2007 at 9:24 PM
And just how accurate are current passive microwave methods, in terms of their ability to successfully detect and characterize sea ice? (This question is neither meant to be naive, nor, rhetorical, it is meant to provoke a serious discussion informed by science and engineering considerations).
Looks like the science of using passive microwave in an attempt to infer areal extent of sea ice is not settled:
http://nsidc.org/data/docs/daac/nsidc0051_gsfc_seaice/TM104647.html
http://nsidc.org/pubs/notes/21/
Click to access 01294432.pdf
http://www.giss.nasa.gov/meetings/seaice1999/session5.html
Click to access 6.1_barry_et_al.pdf
http://www.ghrsst-pp.org/GHRSST-PP-Sea-ICe-Technical-Advisory-Group-(SI-TAG).html
RC, by the way, did allow the pot stirring question about passive microwave to post. But, unsuprisingly, none of the participants there (nor the site’s principles) have dared to touch it with a 10 foot pole. Interestingly, in that same thread, there are people noticing funny things about the purported “areal extent” imagery, but are too dense to ask the follow on questions regarding data validity and the validity of the images derived from them.
Here’s the applicable RC thread:
http://www.realclimate.org/index.php/archives/2007/08/arctic-sea-ice-watch/
To be clear, I do believe that sea ice extent has trended downward since 1979. Prior to that, extent would be a subject of great and needed debate. I also strongly suspect that summer extent has been systemically underreported since 1979. I also am concerned that the algorithms used to purport areal extent may not be completely clean. There could indeed be an ice extent inverted hockey stick, essentially by design. I personally do not have the time to analyze the algorithms. Would be a great project for a PhD candidate.
Alarmists’ map:
Realists’ map and description:
http://pafc.arh.noaa.gov/ice.php?img=ice
THE MAIN ICE EDGE LIES FROM THE WESTERN COAST OF BANKS ISLAND TO 71.3N 132.5W TO 70.8N 135.9W TO 71.0N 138.0W TO 71.2N 143.0W 71.7N 145.0W 72.3N 149.9W 72.9N 152.0W 74.4N 154.8W AND CONTINUES TO THE NORTHWEST. THE EDGE IS MAINLY 1 TO 4 TENTHS NEW…YOUNG…FIRST YEAR THIN AND MULTI YEAR ICE.
FORECAST THROUGH MONDAY…EAST AND NORTHEAST WINDS OF 10 TO 20 MPH WILL CONTINUE AROUND THE VICINITY OF THE ICE EDGE THE NEXT 5 DAYS. THE ICE EDGE MAY MOVE SOUTH AND SOUTHWEST 5 TO 10 NM BY MONDAY AFTERNOON.
A few more Terra Satellite images from today.
The NorthWest Passage – while it has clearly been open for the past 2 weeks, the sea ice is rapidly refeezing and is pushing up on the coast near Inuvik. Any ships trying to get through better go full-out to make it through.
The big melt of the Western Arctic has ended and the ice is refreezing.
False color image with sea ice in Red.
A few more ….
Once again, the alarmists’ map:
And things from the mother of all (USN) realist maps (from a NOAA site):
Click to access currentcolor.pdf
Click to access currentcolor.pdf
Several degress of latitude difference in the ice edge from the international date line to about 160 W.
If the NWP is “open” or semi open – the trip would certainly be harrowing:
Click to access currentcolor.pdf
Click to access currentcolor.pdf
Click to access currentcolor.pdf
Click to access currentcolor.pdf
If someone wanted to risk their boat, I’d say go for it man! 😉
Re: #8
Permanent human settlements existed along the northern, northeastern, and eastern coasts of Greenland for centuries at a time in various periods long before, up to, and including the arrival of the Norse settlements. The fauna and flora utilized by these settlements are indicative of climate conditions warmer than exist at the present time.
Re #13 Steve S, any idea why the Polarstern has been unable to reach the North Pole and deploy the cameras?
It’s August 31 and the window for deployment is closing fast.
RE: #17 – My guess is pressure ridges, but it’s only a guess. The NH sea ice has clearly been in an extremely compressive mode the past few years. Sort of a comedy of errors with NP web cams this year, no?
Meanwhile, out on the Beaufort anc Chukchi Seas:
“FORECAST THROUGH SATURDAY…EAST WINDS OF 10 TO 20 MPH WILL CONTINUE
AROUND THE VICINITY OF THE ICE EDGE FOR THE NEXT 5 DAYS. NEW ICE WILL
FORM NEAR THE ICE EDGE AND WITHIN THE PACK AS TEMPERATURES DROP BELOW
FREEZING. LITTLE NET CHANGE IN THE POSITION OF THE EDGE THIS WEEK.”
Meanwhile, out on the Beaufort and Chukchi Seas:
“FORECAST THROUGH SATURDAY…EAST WINDS OF 10 TO 20 MPH WILL CONTINUE
AROUND THE VICINITY OF THE ICE EDGE FOR THE NEXT 5 DAYS. NEW ICE WILL
FORM NEAR THE ICE EDGE AND WITHIN THE PACK AS TEMPERATURES DROP BELOW
FREEZING. LITTLE NET CHANGE IN THE POSITION OF THE EDGE THIS WEEK.”
Nonetheless, the NSIDC/Crysophere Today hairball continues to grossly underreport areal extent, probably to the tune of 500K to 1M sq. Km.
meanwhile, a guy trying to sail the north route around Russia is having problems with ice and polar bears.
http://www.cowes.co.uk/zonexml/story?cp=0;story_id=3228
RE: #22 – He won’t make it. The area around 90 E never opened. There is old ice fast to shore there. You could walk from Siberia to the North Pole – that has been the case since last fall and will continue to be the case for the rest of this year. And now, the great annual freeze up has begun.
Sorry, I was off a bit on longitude, more like the area in the low 100s E.
Re 17 and 18, the Polarstern can sail through ice 1.5 metres thick at 5 knots, but thicker than that it must ram its way through. This link http://www.sailwx.info/shiptrack/shipposition.phtml?call=DBLK shows the daily position. It looks like a valiant attempt was made to get to the pole on 31 August, but it is now fleeing south. Frau Merckel would have been on the phone. Steve S, how thick is the ice there do you think?
RE: #25 – I’d guess that it’s 2 – 3 m plus pressure ridges. There has been immense compression of Actic ice over the past 2 – 3 years. Lots and lots of persistent wind with a large fetch. Something the usual suspects don’t want to discuss.
RE: #11 – It’s almost funny, but also sad. On that RC thread, in spite of the real world data of the NWS Anchorage Ice desk (used by real fisherman to play chicken with the ice edge) and the Polarstern fleeing south, they continue to obsess on the now-comical psuedo-data of the NSIDC. Completely ignoring reality in order to play the “it will allllllll melllllllt awayyyyyyy!” script, over, and over, and over.
Sorry about the truncated post….I hit the wrong button. What I wanted to ask; What will the impact of this blind acceptance, of what seems to be unreliable data, have on the rputation of the leading figures. Can there be a recovery from such a debacal or are we looking at the end of some scientific careers?
Change of topic. The supposed “North Pole Swimmer” earlier this year, spot lighted by the BBC. I submit that swimming in actual open ocean at the NP at any point this year would have been non physical, utterly impossible. And yet, the Beeb’s article showed the guy doing a racing dive off of an ice floe. So, the question is, where did the guy actually go? And why has no one exposed this as the hoax is must have certainly been? Anyone have more info on this?
Steve S, it’s not uncommon to have openings in the ice pack, even at the North Pole. Remember that it is being driven and moved by the wind. When it crunches up at one place, it perforce must open up in another.
w.
RE: #30 – You had to see the photos. I suspect it was nowhere near the pole. It showed the guy race diving into a huge area of open water. The ice he was jumping off of did not have that appearance of ice I’ve seen at the NP region. The lead did not look like a simple crack. No pressure ridges annywhere near. My suspicion? He was actually just inside the ice edge, probably at 80 Deg N, max. Somewhere up north of Europe. I strongly suspect a complete hoax. I’d love to see the GPS readings. Assuming they were even taken.
His name is Lewis Gordon Pugh. They said he was taken to the geographic North Pole by a Russina icebreaker. His swim was reported to be 1 kilometer, and he completed the swim in just over 18 minutes at 0200 hours on 15 July 2007. There are many reports, a daily diary, and more on various websites.
About 70% of the way through this clip, you briefly see him at his claimed North Pole swim.
Re: #33
Anyone with the fare of $21,900 or more can take a tourist cruise to the North Pole aboard the nuclear powered Russian icebreaker, NS YAMAL. If there wasn’t already a normal lead or crack in the ice at the North Pole, there certainly would be after the icebreaker created one in its passage throguh the ice. The icebreaker uses helicopters to conduct reconnaisance flights in search of the most navigable routes through the ice.
http://www.eaglescry.com/Yamal.htm
http://en.wikipedia.org/wiki/Yamal_(icebreaker)
http://www.polarcruises.com/ship.cfm?pole=Arctic&mainnav=ships&ship_id=21
So it was a hoax – he swam in the opening created by an ice breaker.
Re: #35
There is no particular reason to assume its was a hoax. The Russians are taking many tourist expeditions to the North Pole by aircraft in addition to the NS YAMAL. It is not uncommon for there to be open leads in the ice in the area of the North Pole during the summer season, particularly around July 15th. In addition to ice station BORNEO, there are webcam pictures, satellite photos, and aerial photos which variously show open leads, pressure ridges, melt ponds, and frozen surfaces at various time periods. I don’t remember where I found the Website, but there used to be a site which allowed you to zoom in and out of a series of aerial photographs and satellite photographs of the arctic. You could see everything from the broad overview of the nearest land masses and then zoom in to see the detail of individual melt ponds barely large enough to hold a ship. It was easy to see many open leads and pressure ridges throughout the Arctic ice pack.
It was a hoax, because it was portrayed as “swimmer uses North Pole swim to demonstrate AGW peril …. open water at the NP, oooooooh noooooo!” When in fact, any open water was created by an ice breaker.
By the way, I am well aware of NP web cams, I’ve checked in on them for years. And this year, there was no naturally occurring open water in that area at the time of the swim.
Re: #37
Open water at the North Pole is not at all uncommon, especially in July. You can tell that the open water in the picture is a natural lead, because it is far too wide, long, and uncharacteristic of the broken ice found in the wake of an Arctic icebreaker. When you look at the wake of an Arctic icebreaker, you can see how the broken ice simply floats back to refill the wake and begins to freeze over again. The water seen in the picture with the swimming expedition is open water lacking the broken and refreezing ice found in the wake of an icebreaker. Clearly, the images depicts the open water of a natural lead.
There is no need for a hoax. The Russians have been taking lots of tourists to the North Pole, and many of them have been swimming there in the open waters. The only difference on this occasion was the 1 kilometer distance of the swim.
The comparison of open water at the Pole to an ice-free Arctic Ocean is something of an exaggeration. Typically the areal concentration of open water in the ice pack during the summer is 10%. Therefore, under normal conditions a visitor to the North Pole in late summer should expect to find some open water approximately one time out of ten. The National Snow and Ice Data Center posted satellite imagery from July 26, 2000, and although the region near the North Pole was obscured by thick clouds, a fairly typical summer pattern of jumbled ice floes and frequent leads of open water is evident in the central Arctic Ocean. Among the historical anecdotes related to us about open water at the Pole is the surfacing of USS Queenfish(SSN 651) during summer 1970 through a polynya a few hundred yards across about 500 yards from the North Pole.
While the importance of open water at the Pole has been overemphasized, it is consistent with the mild ice conditions encountered by the Yamal during her transit and the relatively thin ice conditions we observed over a wide area during deployment of the Observatory. It also highlights important trends in recent years.
http://psc.apl.washington.edu/northpole/NPOpenWater.html
You’ll note they are talking about the observations made by scientists from such institutions as the University of Washington in the year 2000, long before the swimming stunt in 2007. It should also be observed that the NS YAMAL and the icebreakers could not have navigated to the North Pole if it were not for the fact that open leads and leads frozen with light ice and first year ice gave the icebreakers access to the North Pole.
On 5 May 2000 the Arctic was still well frozen with the summer thaw still to come in the next couple of months, yet the TERRA/MODIS satellite photograph already shows a vast network of open water leads, frozen leads, polynyas, and melt ponds all across the Arctic Ocean and the North Pole. By the months of July and August, areas of unfrozen sea become larger and more evident.
Throughout the region within the Arctic Circle leads are continually opening and closing due to the direction and intensity of shifting wind and ocean currents. Leads are particularly common during the summer, when temperatures are higher and the ice is thinner. In this image, each pixel is one square kilometer.
Franz Josef Land and the Arctic Ocean
NP0030-39: Sign at the North Pole, with a GPS, Global Positioning System. North Pole. Arctic Ocean. Digitally composed.
NP0033-13: Bather checks a thermometer during the Polar Plunge at the North Pole on a visit of Icebreaker Sovetskiy Soyuz.
NP0031-21: Tourists & russian crew of the icebreaker take part in the ‘Polar Plunge’ when they reach the North Pole.
NP0047-02: Tourists dance around the world at the North Pole by the Russian Nuclear Icebreaker Sovetskiy Soyuz
http://www.arcticphoto.com/newsearch.htm
Re: #38
If you’ve been aware of the North Pole Webcams for years now, you should also have been aware of the fact that none of the North Pole Webcams were anywhere near to the North Pole on 15 July 2007. They’re located on ice floes which drifted far far away from the North Pole by July 15th and could not possibly have monitored the open water lead/s at the North Pole or the NS YAMAL and its activities.
OK, so it wasn’t a hoax. But it sure was cynical.
Re: #40
It is remarkable to see how anyone can be surprised to find thinner ice than seen before in the past fifty years, when you consider the present Solar Maximum and the past fifty years have typically been considerably colder than they have been for around the past 100 to 120 years aside from the equivalently warm period around 1920 to 1940. If anything, the ice may have been thinner than now in the period 1934 to 1939, but there were no satellites and not enough observations to discover the warming effects in the Arctic Ocean. If the next two solar cycles result in another phenomenon like the Maunder Minima, then the polar scientists will have an opportunity to observe an Arctic Ocean with conditions like those some centuries ago.
Of course such an event would afford us an opportunity to see how the great green political machine can conduct a public relatiosn campaign to convince everyone that the Great 21st Century Global Cooling was a direct result of 20th Century anthropogenic greenhouse gas emissions and Global Warming; or is that just being cynical???
I wonder how the accuracy of the instruments are holding up in the Arctic environment? Maybe we can get a grant for Anthony and send him up there to conduct a station survey (grin). Might be a good place to enjoy a nice warm latte.
re: 22 etc
From the “wish I’d said that” file, this from the http://www.alphaglobalex.com editor:
“Although the Church of Global Warming would have us believe that a bikini clad girl on a surfboard could breeze through the Arctic, the reality is very different. The Arctic remains a bitterly cold and forbiding place that does not forgive mistakes.
Sailing status essentially unchanged for solo run — ice-breaker idea also appearing less feasible. A favorable wind that opened what appears to be a drift ice passage (satellite view) is about to end. The risky ~300 mile squeeze solo run requires about 50 waking hours of clear water at ~6 knots. When the wind switches back to North, the passage closes again — doesn’t look good, as of post time, the wind was forecast to switch back N in the next few hours and last for ~3 days.
http://agx.firetrench.com/?p=218 … and p=219!
I have long suspected the NSIDC of underreporting sea ice extent. It may be due to their overreliance on passive microwave remote sensing, which has issues with detection of sea ice below very high concentrations, and issues in general during celestial summer. There are also issues with distinguishing the ice surface itself given the broad and diverse characteristics that such surfaces can have (variations in ice roughness and density, not to mention presence and absence of overlying materials such as snow cover and surface ponds). Finally, even if one has managed to gather what are considered “good” passive microwave data, these data must then be processed by algorithms in order to derive areal extent, peripheral extent, and of course, the visual graphical ice cover images so adored by the media and masses. The opportunities to inject an agenda are not to be discounted. Of course, nothing has been proven nor have any specific accusations been made. Here is one key player at NSIDC, who is also a participant at RC:
http://nsidc.org/research/bios/serreze.html
A final note. Cryosphere Today also relies on the raw data feed from NSIDC (as do a number of others producing sea ice extent derivations). CT runs their own algorithim. CT’s algorithm appears to have been changed earlier this year.
Relatively cloud-free day in the western Arctic. Here is a good image from the MODIS/Terra satellite of the big melt area. Most of the rest of the Arctic has about average ice conditions but not this area. (I posted a bunch of images this morning but the spam filter grabbed it.)
Indeed, “the great melt back of 2007” has really been, all along, “the great Siberian Sea and Chukchi Sea meltback of 2007.” Elsewhere, it has been boringly normal. In fact, the Barents Sea has had a fairly pathetic melt back especially in the NW quadrant (Svalbard has not really had a summer this year). Knowing what we know about currents, one must wonder what if any correlation there is between the rapid cooling of the Pacific and this. Hmmm …. where did the heat go? North … to Alaska …. and beyond?
Interestingly, Judith Curry has had at least some minimal involvement in this field of study.
FYI:
http://nsidc.org/data/seaice/pm.html
As Mr. Spock would say, fascinating:
Click to access ss2_pmseaice_3_5.pdf
The “science” (black art?) of sea ice “measurements” (estimates) is definitely not settled.
Looks like a variant of wait ’til next year http://agx.firetrench.com/?p=220 is the most likely plan!
Looks like a variant of wait ’til next year is the most likely plan!
Sorry for the duplication — spam-guard has been grabbing my posts.
The NSR is definitely going downhill rapidly. It’s been an interesting year. Multiyear ice never really cleared from the shores of the Eastern Laptev Sea. To be fair, if you look at SSTs, the major opening north of the Bering Strait is clearly due to a shot of warm water that went up in there as the Pacific went into neutral / La Nina mode after the short, sharp El Nino last year. If you envisage El Nino as a thermal transient, the wave front reached the Arctic just in time for the melting season, and there you have it. Also, possibly, PDO is flipping. That must also be a factor, if it’s in fact occurring. Let’s see what the Arctic looks like after a few years of definite negative PDO and a quiet period in terms of larger sized El Ninos. That will be the true test of just how much sea ice has declined in any “mean value” sense, with significance at multi decadal time scales.
http://polar.ncep.noaa.gov/seaice/docs/ssmi.auto/ssmi120.html
This is in alignment with a number of other sources I put up earlier in this thread. Note the involvement of NCAR. Another intersting thing, there was apparently something new and different available as of last year, brought to you by a practicioner of one of our “favorite” techniques, P.C. analysis. To wit:
Click to access ss2_pmseaice_3_5.pdf
I wonder how many organizations are now using Toudal’s PC analysis and when did they begin to use it? Was that what changed back in Jan of this year, at NSIDC and Cryosphere Today?
Final comment. I concede that current / recent extent is probably indeed an low record, within the 1979 – present data. So, even if there is monkey business going on, it probably is not significant, per se, within this short span of time. Has AGW impacted sea ice extent? I won’t rule it in or out. One thing to note is that the current summer ice appears to be very dense, and appears to have almost no interstitial open water. It has, in other words, been laterally compressed.
52
The AMO has probably peaked as well, so we should be seeing less warming in the North Atlantic. Not enough data yet to be unequivocal, but the UAH NoPol temperature anomaly, FWIW, may have peaked.
Amusement over in the bunny hutch:
http://rabett.blogspot.com/2007/09/northwest-passage-is-open-and-it-looks.html#links
There are some truly evil people participating at the bunny hutch. We knew that, of course, but still, it is, at times, nonetheless shocking. It’s always good to face up to the mindset one is dealing with, warts and all.
For example:
Anonymous said…
Steve sadlov said; “Some of the “thin ice” in question is sufficiently robust to allow fur seals to safely rest on and traverse the ice. I personally witnessed this on the north shores of Hokkaido… ”
I see (icee, get it?) math is not your strong point — and cut and paste is.
Let’s calculate how thick sea ice has to be to support an adult fur seal lying on its belly, shall we?
This table gives the sea ice thickness to support one person (at rest) 13cm.
Assuming that person is about 150lb and that their feet have a total cross sectional area of about 70 sq inches, that means sea ice 13cm thick will support roughly 2 lb per square inch.
Northern fur seal adults are about 600lb and 6 feet long. Assuming about half that length is touching the ice while they are lying on their belly and that the width of their belly is about a foot yields about 400 square inches touching the ice.
600 lb exerted over 400 sq inches is about 1.5 lb per square inch — which is less than the 2 lb per square inch exerted by a person standing on the ice.
In other words, the 13cm of ice needed to safely support a person is almost certainly sufficient to support a 600lb fur seal.
Lest you try to weasel out by saying “that’s for a person who is not moving”, let me direct you to the very next entry in the table which is for a safe load of .4 ton (800lb) moving slowly across the ice — which would almost certainly encompass a 600 lb seal moving across the ice. For that, only 18cm of sea-ice thickness is required. In other words, still not much.
So, 18 cm of ice would safely support a 600 lb seal moving across the sea-ice.
See the problem with your assumptions — and your math?
In relative terms, 18 cm of sea ice is nothing — or about as close to nothing as you can get without actually having no ice in the arctic.
Q: What’s the difference between an arctic ocean covered by 18cm of sea ice and an open arctic ocean?
A: A few days above freezing temperatures.
8:07 PM
So much stupidity, so little time …..
http://pafc.arh.noaa.gov/ice.php?img=ice
This analysis used to show a much broader area. Time and time again, it was obvious that this analysis, which uses a combination of all available remote sensing and direct (aerial, sea, shore) observations, was showing ice that would never show up in the “sea ice extent” interpretations depicted at NSIDC, CT, et al. In the “before” scope of this analysis, the eastern limit was about half way W-E across Banks Island, with the Western and Northern limits scaling appropriately. To anyone who is not aware that the analysis area was recently (within the past two weeks) shrunken, it might appear that ice extent in the Beufort Sea had suddenly decreased, during a period where it in fact slightly increased.
Is this a mere coincidence …. mere stupidity? I certainly hope so.
2007 is depicted as lowwwwwwwwest NH ice extent minimummmmmmm everrrrrrrrrr ……..
Read this, especially all the interpolation, adjustments and caveats for the pre 1970s data:
http://www.cgd.ucar.edu/cas/guide/Data/walsh.html
Then, look at these data:
http://arctic.atmos.uiuc.edu/SEAICE/timeseries.1870-2007
Now, can someone tell me what the actual NH minimum was in say, 1942?
I thought this whole thing is supposed to be solved by the fill in the number thingey?
“Sorry, but your comment has been flagged by the spam filter running on this blog: this might be an error, in which case all apologies. Your comment will be presented to the blog admin who will be able to restore it immediately.
You may want to contact the blog admin via e-mail to notify him.”
What gives?
SSadlov.
go have fun with Tamino. he’s on ice today
Retrying post from yesterday, which was eaten by filter:
2007 is depicted as lowwwwwwwwest NH ice extent minimummmmmmm everrrrrrrrrr ……..
Read this, especially all the interpolation, adjustments and caveats for the pre 1970s data:
http://www.cgd.ucar.edu/cas/guide/Data/walsh.html
Then, look at these data:
http://arctic.atmos.uiuc.edu/SEAICE/timeseries.1870-2007
Now, can someone tell me what the actual NH minimum was in say, 1942?
Retrying post from yesterday, which was eaten by filter:
Read this, especially all the interpolation, adjustments and caveats for the pre 1970s data:
http://www.cgd.ucar.edu/cas/guide/Data/walsh.html
Then, look at these data:
http://arctic.atmos.uiuc.edu/SEAICE/timeseries.1870-2007
Now, can someone tell me what the actual NH minimum was in say, 1942?
Retrying post from yesterday, which was eaten by filter, Part 1:
Read this, especially all the interpolation, adjustments and caveats for the pre 1970s data:
http://www.cgd.ucar.edu/cas/guide/Data/walsh.html
Part 2……
Then, look at these data:
http://arctic.atmos.uiuc.edu/SEAICE/timeseries.1870-2007
Now, can someone tell me what the actual NH minimum was in say, 1942?
This sucks…. my attempt to post part 2 ….ended up with:
“Sorry, but your comment has been flagged by the spam filter running on this blog: this might be an error, in which case all apologies. Your comment will be presented to the blog admin who will be able to restore it immediately.
You may want to contact the blog admin via e-mail to notify him.”
RE 66. Stop trying to post from your Xbox360 dude.
The problem was not at my end. It was the “Kinda Captcha” spam filter. Problem was, instead of asking me to type in a number, it asked for nothing, ate my posts and said contact the admins. Well clearly they recovered all the affected posts from false-acusation (of being spam) hell.
I tried to post a bunch of MODIS satellite links on this thread earlier and the spam filter caught me as well (but not on other threads for some reason).
Quietly, a rapid change proceeds:
http://pafc.arh.noaa.gov/ice.php?img=icef
Meanwhile ….
These folks as well as NSIDC continue to have severe issues with underreporting ice at the edge. Note in particular how the underreporting of the edge in the Beaufort Sea continues apace. Also, they underreport the edge in the NW Barents Sea, just to name two examples. Also, they underreport ice concentrations less than 60% (6/10ths) – essentially showing it as ice free. During the sunny time of year in the Arctic, they underreport ice that has certain surface conditions such as melt water, slushy snow, and unusual ice textures – they show it as open water. Look, I do not deny that the ice extent has gone very low this year. But was it really an “all time record low?” I remain to be convinced of that.
Even the relatively balanced bunch at the Anchorage NWS Ice Desk only have records back to the 70s. No one can really say how low certain sea ice minima may have been prior to that. Also, some interesting additional things:
OCTOBER 2007 OUTLOOK FOR THE 2007 TO 2008 ICE SEASON.
THE SUMMER ARCTIC ICE COVERAGE IN 2007 WAS A RECORD MINIMUM FOR AS
FAR BACK AS THERE ARE RECORDS. THERE ARE SEVERAL SOURCES ON THE
INTERNET WITH DETAILS ON THIS EVENT. OUR RECORDS OF THE ICE IN THE
CHUKCHI AND BEAUFORT SEAS GO BACK TO THE MID 70S. THE FIRST OF
OCTOBER THE ICE NORTH OF POINT BARROW WAS NEAR 79.5N. WEST OF 155W
THE ICE EDGE TOOK A STEEP DROP TO THE SOUTH. AT 150W THE ICE EDGE
WAS NEAR 75N. AT 145W THE ICE EDGE WAS NEAR 73N AND AT 140W THE EDGE
WAS NEAR 72N. WHILE THIS ICE POSITION WAS A MINIMUM THERE HAVE BEEN
OTHER YEARS WHERE THE ICE NORTH OF ALASKA REACHED SIMILAR LATITUDES.
THESE YEARS INCLUDE 2006…2005…2002 AND 1997. THE EXTREME MINIMUM
ICE HAPPENED IN WATERS NORTH OF RUSSIA. BECAUSE NONE OF THE AFORE
MENTIONED YEARS HAD SUMMER ICE THAT EQUALED ANYTHING NEAR THE MINIMAL
ICE NORTH OF RUSSIA A SIMPLE YEAR GROUP ANALYSIS WAS NOT POSSIBLE. I
DECIDED TO DELAY THIS OUTLOOK TO ALLOW OTHERS IN WEATHER AND
CLIMATOLOGY TIME TO PRODUCE THEIR REPORTS FOR SEPTEMBER AND TO GIVE
ME TIME TO DISCUSS THE ARCTIC WEATHER PATTERN WITH MY CO-WORKERS.
AS THE ICE EDGE NORTH OF RUSSIA MOVED NORTH DURING THE SUMMER GREATER
AREAS OF WATER WERE OPENED TO HEATING FROM THE SUN AND THERE
DEVELOPED A SIGNIFICANT WARM ANOMALY IN THE SEA SURFACE TEMPERATURES
IN THE ARCTIC WEST OF ALASKA. MORE AREAS OF WATER WERE FREE OF ICE
WHEN THE SUN COULD PROVIDE THE MOST EFFICIENT HEATING BECAUSE OF ITS
FAR NORTHERN POSITION. THE QUESTION NOW IS HOW FAST WILL THOSE WATERS
COOL ENOUGH TO FORM SEA ICE. THE HEAT FROM THE SUN IS QUICKLY
DIMINISHING IN THE ARCTIC AS THE THE EARTH NEARS THE NORTHERN
HEMISPHERE WINTER SOLSTICE AND WATER TEMPERATURES IN THE BEAUFORT AND
CHUKCHI SEAS ARE COOLING QUICKLY.
I USED THE NOAA CLIMATE PREDICTION CENTER/S REANALYSIS WEB SITE TO
LOOK AT WEATHER AND SST PATTERNS FOR 2007…2006…2005…2002 AND
1997. FOR ALASKA THE WINTER OF 2006-2007 WAS A HEAVY ICE YEAR AND I
HAVE OFTEN BEEN ASKED IS THIS WINTER GOING TO BE AS BAD FOR SEA ICE.
MY ANSWER IS NO. THE LARGE SCALE WEATHER PATTERNS THIS FALL ARE NOT
SIMILAR TO 2006. THEY ARE SIMILAR TO 2005 EXCEPT THE 2007 PATTERN
SEEMS TO BE A LITTLE STRONGER…POSSIBLY DUE TO THAT EXTRA HEATING
FROM THE SUN IN THE WESTERN ARCTIC OCEAN. SO THAT IS MY THINKING FOR
THIS UNUSUAL YEAR. HERE IS MY SEA ICE OUTLOOK.
2007-2008 WINTER ICE OUTLOOK…
EVENT 2007-2008 OUTLOOK
SIGNIFICANT ICE IN WEEK OF OCTOBER 29
KOTZEBUE SOUND
MINIMAL ICE IN WEEK OF OCTOBER 22
NORTON SOUND
SIGNIFICANT ICE IN WEEK OF NOVEMBER 11
NORTON SOUND
ICE IN KUSKOKWIM BAY WEEK OF NOVEMBER 5
ICE TO SAINT PAUL ISLAND LAST WEEK OF JANUARY 2008
SOUTHERN ICE EXTENT IN 56.5N NEAR 170W IN EARLY FEBRUARY
BERING SEA
FIRST ICE IN COOK INLET FIRST WEEK OF NOVEMBER
SIGNIFICANT ICE IN WEEK OF NOVEMBER 12
UPPER COOK INLET
SIGNIFICANT ICE NEAR NIKISKI WEEK OF JANUARY 7 2008
SOUTHERN EXTENT OF ICE ACROSS FROM ANCHOR POINT
IN COOK INLET MAIN CHANNEL LAST WEEK OF FEBRUARY 2008
ICE IN KACHEMAK BAY FIRST WEEK OF FEBRUARY
BUT NOT AS MUCH ICE AS 2006
KCOLE OCTOBER 2007
$$
Yesterday I was looking a print of the Eastern Hemisphere sheet of Mercator’s 1623 world map. It had a very interesting depiction of the ice edge. In the SH, it showed an extremely conservative depiction, with ice extending well beyond what may have been likely then or during the previous 100 – 150 years. Meanwhile, in the NH, it showed what appeared to be a summer minimum situation. And a quite believable one at that. What was fascinating was that the situaton was not far different from what we had with this year’s minimum. The only difference was that the western “peninsula” of ice, rather than touching Svalbard, touched Russia along the Kara Sea. The eastern “peninsula” of ice touched quite near where this year’s one touched, ~ the transition zone between the Laptev and East Siberian Seas. Like this year, the East Siberian Sea was open. I thought a bit about this, based on who Mercator’s customers and suppliers would have been at the time. His suppliers for sea ice data would have been contemporary mariners, other cartographers, and ones of the past via their own records. He’d realistically have benefited from data since about 1500 or so. His customers would have been long distance merchants / traders and explorers. Showing a very conservative SH made sense because firstly there was less data and secondly, his customers would want to know how far south they could safely plan on sailing for passages to and from East Asia. If you sail with the circum Antarctic winds, you get there faster (around the Cape of Good Hope on the way out, and possibly around the Horn on the way back). Showing more accuracy for the NH would have been of interest to northern sea route travelers. It is interesting that if you assume that he depicted a sort of compilation of the average past summer ice edge for the NH, he was probably showing ~ the situation in the late 1500s. I wonder what the situation was in 1400 or in 1350?
I would add that Mercator’s maps were mostly accurate in terms of depicting the shapes of shorelines, the only problem areas being the Far East and Americas due to lack of data. His depiction of the shoreline from the Barents Sea to the East Siberian Sea could only have been obtained from marine origins, astrolabe in hand, etc.
http://en.wikipedia.org/wiki/Medieval_European_maritime_culture
re 74:
I bought this week the Amsterdam edition of the map of the North Pacific by Delisle and Buache (1750), which is
the first “accurate” map of the region. Even on that map there are a lot of ghost islands depicted.
(google “Buache Pacific” for more images.)
re 73:
Gerardus Mercator died in 1594, perhaps you meant his 1587 map?
NOAA Arctic Report Card 2007 Link
RE: #77 – What I saw was captioned as a 1623 map, so my guess is that whoever wrote that caption was confused. It was probably some sort of reproduction, then, of the actual Mercator map, or, the person who wrote the caption was simply flat out wrong.
RE: #78 – Facinating. It would appear that there is synchronizaton of some sort between the PDO and the AO. Also between PDO and air temp anomalies in the Arctic.
If you look at the Barrow Sea Ice Cam right now, it looks like ice is just offshore.
See http://www.gi.alaska.edu/snowice/sea-lake-ice/barrow_webcam.html
RE: #81- That’s right. The Beaufort Sea is nearly all covered now. Of course Cryosphere Today and Bloom’s fave, NSIDC, with their flawed passive microwave satellite remote sensed data, still show open water between Barrow and about half way upon Banks Is – wrong, wrong, wrong!
Re #81/82,
Our youngest daughter, working as helicopter pilot at the North Slope (Prudhoe Bay), reported that the sea was already frozen two weeks ago, strong enough to stop supplies and get persons from/to the exploration/drilling islands before the coast by boat. As long as the sea ice isn’t thick enough to support truck loads, they have a lot of extra work to do.
The expedition which got through the Northwest Passage (with an icebreaker) noticed that the passage started freezing over on 10 October (see http://news.bbc.co.uk/2/hi/science/nature/7033831.stm )
Latest Anchorage NWS Ice Desk map for Chukchi and Beaufort:
http://pafc.arh.noaa.gov/ice.php?img=ice
And, the latest ice extent interpretation (interpolation?) by Cryosphere Today (using NSIDC raw data):
Are there problems with passive microwave remote sensing of ice extent? (the method used by CT / NSIDC)
NWS says no ice off Barrow, but the webcam shows plenty of ice.
NWS Ice Desk actually says shorefast ice with a bit of 4 – 6 tenths strip ice further offshore, at Barrow.
The “big gap” is freezing over fast, much faster than I would have imagined. In the East Siberian Sea, the freezing is happening so fast that areas of abnormally warm water are being encircled and stranded. Cryosphere Today continues to depict an excessively pessimistic rendition of areal extent – the flaws of passive microwave remote sensing will be the downfall of objective efforts to characterize areal extent. Of note, the zero degree C isotherm is well to the south of the ice edge, nothing can stop the rapid freezing now. The critical 4 deg C isotherm is now within the wider part of the Bering Strait. With a possible 1976 – 1977 like big climate shift at least an even possibility, it will be interesting to see how things progress over the next 2 to 3 seasons.
Note, 1976 – 1977 like, but in the opposite (cold) direction.
Looks like I am not alone in questioning what is commonly depicted as “The Holocene NH Sea Ice Extent Record:”
http://www.worldclimatereport.com/index.php/2007/10/30/arctic-sea-ice-another-hockey-stick/#more-280
Steve Sadlov, I’ve noticed that the CryosphereToday site has shown some remarkably “fast” refreezing of the western Arctic ocean (north of Alaska & NE Siberia) in October. To me this seems to support your thoughts that areas of partial ice-cover had been underreported & are just now coming into their (poor?) method’s “radar”.
RE: #90 – Not only have you hit the nail on the head, but also, I have long noticed that CT tends to lag the “real world” charts done by various local groups (for example, Anchorage NWS doing Chukchi and Beaufort) by 1 to 2 weeks even during a rapid refreezing phase. So, they underreport moderate concentrations and fail to discern the real ice edge. These are both well documented non trivial issues with passive microwave. Many papers on this. In fact, when passive microwave was first used back in the late 60s and early 70s, these issues were so bad, it could not be used at all for this purpose. By the way, a little bird told me passive microwave was actually developed for assaying ground cover on the continents, including a moderately effective job of assaying snow cover in non forested areas. In other words, the real customers were farmers and ranchers.
Here is a (mildly) interesting time series.
One line shows the Arctic air temperature (70N to 90N) anomaly while the other shows the sea surface temperature (SST) anomaly for the far north Atlantic. I define the far north Atlantic as the region from the British Isles northward to 75N, and between Greenland and Scandanavia.
(The anomalies are for the warmer half of the year (July-December), which is when open water is greater and which avoids the confounding effects of sinking water and ice formation on surface temperature. The data source is NCEP reanalysis, for better or worse.)
The hatched green region is the period when the AMO apparently switched phase and when the thermohaline circulation increased.
My conjecture is that, for natural reasons, there was an increased flow of warm water into the far north Atlantic at the time of the switch, which put both sensible heat and water vapor into the Arctic atmospheric circulation. It may have also injected warmer water into the ice-bearing regions, which affected ice activity.
Now, this is not the whole story of Arctic warming and perhaps just a minor player, but I think it is part of the story.
Here is an more-interesting SST time series.
This compares the far north Atlantic SST in the previous warming (1920-1950) with the current warming (plot starts at 1988). These are anomalies from the same base period, so they are comparable.
Things of interest:
* the current SSTs are running 0.1C to 0.2C warmer than in the earlier period
* the rate of rise in both warmups is about the same
* the peak in the 1930s was 10 to 15 years after the rise began. Temperatures then began a slow, irregular decline stretching into the 1970s.
* I wonder if the strong 2006 spike played some role in the 2007 Arctic sea ice decline
* 2007 to-date is running much cooler than 2006 (I use an estimate in the plot, using four months of data)
* if the natural factors are comparable then perhaps we’ve seen the cyclic peak in the current far north Atlantic SST. Now, AGW and/or solar may play a role and the absolute value of SST is higher now than in the 1930s but the cyclic (detrended) peak may have been reached.
FYI:
Click to access currentcolor.pdf
Click to access currentcolor.pdf
Got Weatherby? Maybe as early as New Year’s Day this time … you know, those sad eyed, nearly extinct, widdle white fluffy thingeys …
As of about 10 days ago, it was readily apparent that, even using the highly inaccurate methodology employed by NSIDC and Cryosphere Today to estimate arreal sea ice extent in the NH, we would shortly reach the lowest anomaly in at least a year. So what happened? Well, since that time, the ice extent for Nov 2006 was increased (“adjusted”). And now, interestingly, there seems to be a slight downward deflection in the current extent figure. I’d be the last person to accuse these folks of cooking the books …. NOT!
It won’t be reported in the main stream media, but, even according to the flawed, understated passive microwave / “interesting algorithm” methodology used by Cryosphere Today, NSIDC, et al, at present, we are actually ahead of where we were at this date last year in terms of NH sea ice areal extent. In fact, the anomaly is probably at its lowest absolute value in well over a year. Naturally, winds may cause a reversal. But I figure, since much hay was made of a particular low point earlier this year, ostensibily the lowest since the late 1970s (but perhaps not as low as the early 1940s), I will make equal hay about various short term relative high points. One must even wonder about the baseline for the anomaly. It would appear that the “amomaly” tends to hang near a level of -1 M Km^2 with excursions, but it always seems to want to return to this value. Perhaps there is an error of similar magnitude in the supposed “baseline” against which this “anomaly” is assessed.
The “sea ice doom” narrative brought us to “lowwwwwwwest summer minimum extent in X yearrrrrrs” late this past summer. The important next step in the narrative is “and there was not full recovery during the winter that followed.”
Prediction: Some time between Mar 1 and April 15, there will be the following declaration made by the “sea ice doom” crowd: “Lowwwwwwwwest winter maximum in Y yearrrrrrrs.” And you can take that to the bank.
you are wrong on everything.
we are carefully looking at the trend. extreme events like this, are just a good way to rise awareness, for what is happening.
if you had anything, beyond a rolling “r”, you would bring it up, wouldn t you?
Got yer goat there pal. Nyuk, nyuk …
The ever so critical 4 deg C isotherm is now passing the Aleutians. Many of you recognize this as the triple point. Oddly, the NWS progs a light ice year for the Bering Sea. In their favor, although the Chukchi has continued to be at or below 0 deg C for some time now, ice formation is slow. Maybe there is something to that oil sheen / surfactant thing. Who knows.
Steve S I see that the Cryosphere Today NH ice area anomaly time series has gone blank at the moment (16 Dec), and their long-term chart is blank after 1998. Another revision in progress?
Re #97 – Steve S. – Most “reports” I see show the present as the lowest extent of sea ice in the summer. Which reports would give me a good report on the 1940’s compared to the present which you referred to in this post?
Thanks.
Perhaps they will fix the graphing showing 15-20% negative anomalies in arctic regions that are completely dead of winter ice-locked.
Looks like Cryosphere Today is really hosed. Now they are showing June 2006 – June 2007. Date may be different than shown previously. It shows an extent max above climatic mean, in May 2007!
RE: #104 – That is a clear example of an ice edge – land edge error. Most “algorithms” for cpnverting passive microwave data to extent, throw out pixels located within a certain distance of the land edge – this is a “fix” to the issue whereby passive microwave cannot “see” the difference between ice and land (especailly snow covered land). They “apply” a map of the land edge to the sdata in order to target pixels for excision. And some would call this science!
I hate my fat fingers (and this is a normal desktop keyboard – lap tops are even worse).
RE: #107 – there are also diffraction concerns, whereby it is felt that the land can cause “false positives” for sea ice directly adjacent to the land. This is also part of the rationale for throwing out pixels at the interface.
Re: 105
Steve, you should peruse http://www.archive.org‘s versions of that file. The file archived on Jun 04 2007 is massively different to the one they have up at the moment – about 25% difference in sea ice minima!
Now the chart has gone over a cliff ….
“Dave? What are you doing Dave? Dai-sy … dai-sy …. …… ”
does … not … compute …
RE: #103 – There are no completed data prior to the early 1970s, only guesses.
What a difference a month makes:
…JANUARY 2008 YEAR GROUP ANALYSIS…
THE YEAR GROUP FOR THE FIRST OF JANUARY IS 1999. THE WINTER OUTLOOK
FOR THE BERING SEA AND COOK INLET WILL BE AMENDED TO THIS PRODUCT
TUESDAY MORNING.
KCOLE JANUARY 2008
Globally, sea ice shall soon be at a record high, versus the same calendar points of previous years. The global anomaly is positive and in an unnnnnnnnprecedented steep rise. Well, at least, unnnnnnprecedented in 29 years.
Some more details have been added:
…JANUARY 2008 YEAR GROUP ANALYSIS…
THE YEAR GROUP FOR THE FIRST OF JANUARY IS 1999.
THE ICE IN THE BERING AND CHUKCHI SEAS AT THE START OF JANUARY 2008
HAS REACHED A POINT WHERE THERE ARE SEVERAL PAST YEARS WITH SIMILAR
ICE FOOT PRINTS. THERE IS…HOWEVER…A DIFFERENCE IN ICE THICKNESS
WITH THE ICE IN THE WESTERN BERING AND NEAR RUSSIA BEING THINNER THIS
YEAR. I USED THE YEARS 1999 AND 1996 FOR COMPARISON TO 2008 WITH 1999
BEING THE BEST MATCH WHEN METEOROLOGICAL CONDITIONS ARE COMPARED
ALONG WITH THE BASIC ICE POSITION.
BERING SEA 2008 WINTER ICE OUTLOOK.
EVENT 1999 1996 2008 OUTLOOK
ICE TO ST MATTHEW 11 JAN 10 JAN 6 JAN
ICE TO ST PAUL 22 MAR NO BRIEF PERIODS MID
FEB THRU MID MARCH
SOUTHERN EXTENT 56.7N/167.6W 58.2N/168.5W 56.5N TO 57N
WEST OF 165W 26 MAR 25 MAR BETWEEN 166W TO 168W
MID MARCH
EXTENT ALONG BERING FALSE PASS PORT HEIDEN FALSE PASS
SIDE OF AK PENINSULA
COOK INLET 2008 WINTER ICE OUTLOOK.
1996 WAS NOT USED IN THE COMPARISON FOR COOK INLET.
EVENT 1999 2008 OUTLOOK
GREATER THAN 50 PERCENT COVERAGE 20 JAN 18 JAN
PERCENT COVERAGE SOUTH OF KALGIN
LOWER COOK INLET LESS THAN 7 APRIL 4 APRIL
30 PERCENT COVERAGE…RETREAT
LOWER COOK INLET OPEN WATER 11 APRIL 9 APRIL
UPPER COOK INLET LESS THAN 12 APRIL 10 APRIL
30 PERCENT COVERAGE
“The algorithm did it”…
This is a brilliant illustration of how the algorithm artificially lowers the areal extent estimate. Look at the areas where sea ice fills in the Arctic Ocean up to the shoreline (at this point in the season, essentially, the entire shoreline). See the jagged gap between the shore and the depicted ice edge? That is done by the algorithm. It is because passive microwaver remote sensing cannot really tell the difference between the (snow covered) sea ice and the (snow covered) land. Therefore, in order to avoid the program “blowing up” there is a hack to insert an artificial gap. The gap is created by layering the known shoreline data in, and arbitrarily inserting a crack in the ice that has a set width. In the past, some have wondered how a filled in Arctic can show less than 100% coverage. This is the answer.
re 114. anomaly method solves all problems.
I can assert, based on personal observations made today, of snow cover in my area, that the below methodology misses many regional sized areas of snow cover:
There are a number of areas, several square Km in size, near the West Coast, which are not shown. Collectively they would add up to a handsome area. More systemic weaknesses with passive microwave.
It is interesting that the Southern hemisphere reached a record sea ice extent anomaly in the middle of December 2007. 2 million sq. kms above normal.
The global sea ice extent, north and south combined, went over 1 million sq. kms above normal as well.
How can all this ice be melting at a record rate when the freezing rate is above normal?
Steve S #116
Compare and contrast (link).
Note in particular the patch of snow cover extending almost to the gulf coast.
In the Bering Sea, the ice edge continues its rapid advance and is expected to reach the Pribiloffs this week. There are SSTs of -1 deg C, a bit south of the ice edge. Several weeks to go prior to the typical annual maximum time frame.
1955 0r 1956 USAF 4th SSS Strat.Supp.Sq. SAC
The 4th SSS supported the T-3 personnel with supplies, Flying C-124
cargo planes to & from T-3. I wanted to go but my ‘secret’
security clearance did not allow me on a TS mission. Our C-124
was equiped with special tires that allowed for extra braking when
landing on ice.
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