Sea Ice 2009

For sea ice devotees.

438 Comments

  1. Billy Ruff'n
    Posted Mar 29, 2009 at 5:05 PM | Permalink

    OK, I’m a devotee. I check cryosphere daily. But, did I miss something or is there something missing in the post.

  2. rephelan
    Posted Mar 29, 2009 at 5:10 PM | Permalink

    Be nice, Billy. He may still be jet-lagged. I’ll bet the rest turns up shortly.

  3. Posted Mar 29, 2009 at 5:34 PM | Permalink

    Here’s a post I did a while ago about sea ice, it kind of applies to both topics going on. I downloaded the gridded data from the NSIDC and plotted trends. You can see from the plots where the ice is growing in the antarctic.

    http://noconsensus.wordpress.com/2009/02/07/gridded-antarctic-sea-ice-trend/

  4. crosspatch
    Posted Mar 29, 2009 at 7:43 PM | Permalink

    Well, 2009 is probably going to be pretty important without any additional comment. According to the arm waivers, 2009’s September minimum should come in at less than 2008’s did. Remember, the ice is “disappearing”. And if 2009 comes in with a minimum greater than 2008 was (which is what I expect to see, btw) then we have two successive years of increased ice at minimum or … recovery from the 2007 anomaly, which isn’t supposed to happen.

  5. Posted Mar 29, 2009 at 7:56 PM | Permalink

    I definitely feel this post is missing something…

  6. Alan Wilkinson
    Posted Mar 29, 2009 at 8:13 PM | Permalink

    This is what is missing: Steve’s note: (#740),

  7. Brian M Flynn
    Posted Mar 29, 2009 at 8:38 PM | Permalink

    Are the aerosols from Mt Redoubt more likely than not to increase the NH ice extent for the next year or so?

    • Andrew
      Posted Mar 29, 2009 at 8:46 PM | Permalink

      Re: Brian M Flynn (#8), Don’t count on it. Especially considering the fact that if that ash gets on the ice, it will make it melt…

    • Posted Mar 29, 2009 at 8:57 PM | Permalink

      Re: Brian M Flynn (#8),

      There doesn’t seem to be much sign of an ash plume on the recent sat photos (check the top rh corner):

  8. DJ
    Posted Mar 29, 2009 at 9:00 PM | Permalink

    Here’s the latest Jet stream Map of Alaska. It doesn’t look like much of the dust will head for the Artic this time. Here’s the site:

    http://www.wunderground.com/US/Region/Alaska/2xpxJetStream.html

    • Posted Mar 29, 2009 at 9:19 PM | Permalink

      Re: DJ (#11),

      The Redoubt site gives an altitude breakdown:

      • DJ
        Posted Mar 30, 2009 at 2:16 PM | Permalink

        Re: Phil. (#12), Thanks Phil,your chart verifies the Jet Stream!

        • Posted Mar 30, 2009 at 3:02 PM | Permalink

          Re: DJ (#48),

          Yeah, but it’s NOAA’s not mine. It’s been consistent for the high altitudes heading east, with the lower than 20000′ winds making occasional excursions to the north. I’ve not seen any indications of plumes on the sat photos though.

  9. Posted Mar 29, 2009 at 10:39 PM | Permalink

    Nothing to See… move along now… ;-)

  10. AndyW
    Posted Mar 29, 2009 at 11:01 PM | Permalink

    I guess that means that some peoople have not been following our much loved old thread! Thanks Steve for the new one.

    Although I think the minima will be higher than last years I wouldn’t be surprised, and would find it more interesting, if it is lower.

    Regards

    Andy

  11. Posted Mar 29, 2009 at 11:14 PM | Permalink

    Here is a post I wrote a little while ago when the whole deal with George Will was going on. Now it is on topic over here!

    IPCC sea ice forecasts.

    • Steve McIntyre
      Posted Mar 29, 2009 at 11:20 PM | Permalink

      Re: Nicolas Nierenberg (#15), Nicolas, nice post. Have you by any chance looked for digital versions of the IPCC sea ice forecasts? Lucia enjoys these things.

      • Posted Mar 30, 2009 at 9:29 AM | Permalink

        Re: Steve McIntyre (#16), By digital I assume you mean numerical :-). No I haven’t looked around for that although they must exist.

        Re: Phil. (#17), You can’t be serious, as others have noted. There is a zero to positive trend in SH sea ice over the measurement period as reported by many. You can argue about causes and meaning, but not that. Using your type of logic I guess we can forget about sea ice since it is currently at the long term mean.

    • Posted Mar 30, 2009 at 12:01 AM | Permalink

      Re: Nicolas Nierenberg (#15),

      Really? Minimum global sea ice area in 1979 was ~16.5Mm^2, minimum global sea ice area in early 2009 was ~15.1Mm^2.
      Also where do you get the idea that the antarctic sea ice has increased over the last 30 years? SH sea ice area max in 1979 ~15Mm^2, in 2008 ~15Mm^2, in 1980 min was ~1.7Mm^2, in 2009 min was ~1.7Mm^2.

      • Posted Mar 30, 2009 at 7:06 AM | Permalink

        Re: Phil. (#17),

        This is what I got. I’m not too sure how it will work in the thread.

        I spent a lot of time on this and think the data for ice area is of decent quality. The problems with the sensors described by the NSIDC are reasonably well managed. The antarctic may have points which are similar to today but there has been a general upward trend of about 24,000km^2/yr

        From the gridded Ice data globally I got about a half million sq kilometer loss in global ice area between Jan 09 and Jan 07 I used Jan because that’s when I was working on it. It doesn’t seem like much of a trend either way to me considering there is 20 Million Km^2 of sea ice area and it’s hard to imagine the ice is currently outside of expected natural variation.

        I did it myself because the gridded data is up to date and can be obtained real time. This happened right about the same time the latest antarctic paper came out so I haven’t really finished it yet but I did get the important numbers.

        http://noconsensus.wordpress.com/2009/02/08/global-sea-ice-trend-from-gridded-data/

        All of the ice numbers I used are Area rather than extent.

        • Posted Mar 30, 2009 at 8:07 AM | Permalink

          Re: Jeff Id (#20),

          Oops I meant half million sq kilometer loss between Jan 1979 and jan 2009.

      • Posted Mar 30, 2009 at 7:57 AM | Permalink

        Re: Phil. (#17),

        Also where do you get the idea that the antarctic sea ice has increased over the last 30 years?

        From Cryosphere today or from NSIDC

        or from Comiso and Nishio, J. Geophys. Res. 113, C02S07 (2008).

      • Jedwards
        Posted Mar 30, 2009 at 9:52 AM | Permalink

        Re: Phil. (#17), Ah, Phil,…I think you are guilty of pulling a “George Will” on your ice data by comparing a purely arbitrary start date to a purely arbitrary end date. Even though I’m not convinced that linear regression is the “right” way to go (rather see how a spectral transform applies), a simple OLS fit of the SH sea ice data gives a mildly positive trend.

        • Posted Mar 30, 2009 at 10:34 AM | Permalink

          Re: Jedwards (#28),

          Ah, Phil,…I think you are guilty of pulling a “George Will” on your ice data by comparing a purely arbitrary start date to a purely arbitrary end date.

          Quite deliberately since that standard was set by others here, I guess irony is lost on you?

          a simple OLS fit of the SH sea ice data gives a mildly positive trend.

          Does it? What data and with what confidence interval?

          Re: Andrew (#26),

          Not withstanding Phil’s comments, which ironically use a George Will-esque type analysis, the trend in SH sea ice is pretty obvious:

          What’s obvious is that there is no significant trend in area over the last 30 years, of course if you go back a little further there was a strong negative trend.

          Monthly Antarctic sea-ice extent anomalies, 1973 to 2000, relative to 1973 to 1996. The data are a blend of National Ice Center (NIC) chart-derived data (Knight, 1984), Goddard Space Flight Center satellite passive-microwave (Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I)) derived data (Cavalieri et al., 1997) and National Centers for Environmental Prediction satellite passive-microwave derived data (Grumbine, 1996). It is uncertain as to whether the decrease in interannual variability of sea ice after about 1988 is real or an observing bias.

          Note the ‘typo’ in the axis description, it should of course be 10^6 km^2.

          Of course plotting the trend in monthly anomaly as most have done here does not address the question of what the trend in antarctic sea ice area is. Perhaps Jeff could plot something more meaningful such as the trends in the min and max for example?

        • Andrew
          Posted Mar 30, 2009 at 10:59 AM | Permalink

          Re: Phil. (#30), I’m not sure how you get “no significant trend” in the last thirty years. Its up. If you can’t see it visually, calculate it yourself. I don’t know the origin of your chart which “goes back a little further” but it isn’t surprising-earlier there was warming-more recently, there wasn’t. Clearly you can’t fit a linear trend to that data, in which a clear “shift” is obvious. Here’s a good question for you-where’s the similar data for the NH?

        • Posted Mar 30, 2009 at 11:12 AM | Permalink

          Re: Andrew (#31),

          I’m not sure how you get “no significant trend” in the last thirty years. Its up.

          Not much ‘up’ showing here! You’re claiming a ‘significant trend’, prove it.

          I don’t know the origin of your chart

          Then perhaps you should read the legend.

          Here’s a good question for you-where’s the similar data for the NH?

          In the CT database for a start.

        • Posted Mar 30, 2009 at 11:24 AM | Permalink

          Re: Phil. (#32),

          It sound’s like you guys have a pretty good war going on so I don’t want to step in the middle. In your previous post #30 the data uses is in my mind questionable because it comes from a wide variety of sources and required quite a bit of manipulation to assemble. (it still could be right) I’m just saying that I avoided it as do many of the pro’s when discussing trend. I think that is why it was ended in 02.

          The graph you show in #32 is the raw output and is the same data as in my anomaly plot in #20. Which has a slight positive trend of 24,000 km^2/year. It doesn’t mean very much to me either way though.

          I just don’t believe there’s enough trend to worry about. Them polar bears and penguins aren’t going to need water wings for a long time.

        • Posted Mar 30, 2009 at 11:35 AM | Permalink

          Re: Jeff Id (#33),

          Jeff Id:
          March 30th, 2009 at 11:24 am

          The graph you show in #32 is the raw output and is the same data as in my anomaly plot in #20. Which has a slight positive trend of 24,000 km^2/year. It doesn’t mean very much to me either way though.

          Yes but they’re both monthly anomalies which are not pertinent to whether the sea ice is increasing or not. Look at the last SH cycle for example, for most of the year except for the max and min the anomaly was positive, all it tells us is that the transitions between extrema are different. In any case that trend you report isn’t significant, it has confidence intervals of ~±50,000 km^2/yr. Try plotting the max and min as I suggested.

        • Steve McIntyre
          Posted Mar 30, 2009 at 11:40 AM | Permalink

          Re: Phil. (#35), if you calculate the trends on JFM and JAS anomalies (cf AR4 Fig 10.13), both are non-significant positive.

        • Posted Mar 30, 2009 at 12:09 PM | Permalink

          Re: Phil. (#35),

          Odd, of course the monthly anomaly is pertinent. You get almost the same results from the temperature dataset as well.

          all it tells us is that the transitions between extrema are different.

          It also tells us that ice was above the mean for that period.

          Plotting max/min reduces the amount of available data. I’ve read some of the arguments for this but they deal with other issues. e.g. arctic minimum ice is the critical point because it is more responsive to the thickness of the sheet. Most of these arguments happened around 2006 and 07 I believe because of the sharp bottoms to the arctic ice trends.

        • Steve McIntyre
          Posted Mar 30, 2009 at 11:24 AM | Permalink

          Re: Phil. (#30),

          Phil, c’mon, using a graphic from IPCC AR3 rather than AR4 is a little opportunistic. The 30-year trends in AR4 are from satellite data; the AR3 graphic that you used spliced non-satellite data that wasn’t used in AR4. Why they didn’t use it, I don’t know. Perhaps there is a non-homogeneity that needs to be articulated.

          In the 30-year satellite period, there are non-significant upward OLS-trend in both winter and summer sea ice area. IT seems to me that the more intriguing issue is not whether the upward trend is significant (it isn’t) but whether the difference between the observed trend/nontrend is significant relative to AR4 model projections of noticeable declines.

        • Posted Mar 30, 2009 at 11:36 AM | Permalink

          Re: Steve McIntyre (#34), And my point is a slight variation. I can’t see, based on AR4, why global sea ice isn’t the relevant statistic rather than picking one or the other.

        • Steve McIntyre
          Posted Mar 30, 2009 at 11:42 AM | Permalink

          Re: Nicolas Nierenberg (#36), nor can I. I did some calcs last year on GLB anomaly and will try to refresh them some time. I’ve just sent a request to Bracegirdle of Connolley and Bracegirdle, the senior partner of which is the renowned Wikipedia litigator, asking for AR4 sea ice model projections. Maybe he’ll be as cooperative as Santer.

        • Ian Sims
          Posted Apr 7, 2009 at 10:00 AM | Permalink

          Re: Phil. (#30), Your “strong negative trend” in the blended data coincides with a period of global cooling. A quick mental Mannian calibration on the blade of this backward hockey stick implies more ice during warming periods. Not what the Team doctor ordered, which is why, I suppose, we don’t see this chart very often.

        • bender
          Posted Apr 7, 2009 at 10:07 AM | Permalink

          Re: Ian Sims (#104),
          The globe (where the alleged “cooling” is occuring) is not the Arctic (where the sea ice extent is declining). Back to calibration school, Ian.

        • Ian Sims
          Posted Apr 7, 2009 at 10:59 AM | Permalink

          Re: bender (#105), Thanks, Bender !!

        • Posted Apr 7, 2009 at 12:53 PM | Permalink

          Re: Ian Sims (#104),

          Re: Phil. (#30), Your “strong negative trend” in the blended data coincides with a period of global cooling. A quick mental Mannian calibration on the blade of this backward hockey stick implies more ice during warming periods. Not what the Team doctor ordered, which is why, I suppose, we don’t see this chart very often

          Not global cooling, in fact SH warming which considering the graph is of the antarctic seems reasonable.

        • UK John
          Posted Apr 7, 2009 at 1:30 PM | Permalink

          Re: Phil. (#108),

          Nice one Phil, we have seen that graph before and know all about it!

          Don’t distract us, back to the Ice debate! that is what you add value to.

        • bender
          Posted Apr 7, 2009 at 1:46 PM | Permalink

          Re: Phil. (#108),
          Phil,
          Thanks for adding value to the debate by clearing up Ian Sims’s misconception and misinformation. The globe is not in fact “cooling”, athough temperatures have flattened in the past decade. More to the point: the NH and the Arctic in particular, are anything but “cooling”. That is the point Ian should have spoken to. Thanks again for supporting your claims with data.

        • Ian Sims
          Posted Apr 7, 2009 at 2:31 PM | Permalink

          Re: bender (#110), bender, Phil, I accept my status as someone with much to learn in Climatology. But Phil’s chart in #30 was referring to the Antarctic, not the Arctic. I don’t understand, bender, why you think the Arctic comes into this.

          I was being flippant regarding “calibration” and backward hockey sticks, but I was picking up on the relationship between falling (or at least not rising) global temperature and declining Antarctic sea-ice area in the period of the strong negative trend in Phil’s chart – 1973 to say, 1978.

          Phil wants to fine-tune the temperatures. OK, Steig notwithstanding, let’s get closer to the Antarctic and look at GISTEMP Annual mean Land-Ocean Temperature Index for 90S – 64S, 1973 to 1978. Numbers are: 34, 73, 37, -24, 25, 9, -21. That’s a “strong negative trend”.

          That said, obviously this is a ridiculously short time period to mean anything. I was just making an acerbic aside keying off Phil’s chart and his description of a strong negative trend. I’m not and was not claiming the NH and the Arctic are cooling. Peace.

        • Ian Sims
          Posted Apr 7, 2009 at 2:44 PM | Permalink

          Re: Ian Sims (#111), whoops, drop the -21 in 1979. Sorry. It’s still a strong negative trend though!

        • bender
          Posted Apr 7, 2009 at 2:51 PM | Permalink

          Re: Ian Sims (#111),

          I don’t understand, bender, why you think the Arctic comes into this.

          My bad. I jumped into the thread midway and assumed when the OP read “sea ice 2009″ it was referring to the Arctic. Detention for me.

        • Ian Sims
          Posted Apr 7, 2009 at 3:05 PM | Permalink

          Re: bender (#113), No problems, bender. When I don’t get what you’re saying it’s usually me that’s missed.

        • UK John
          Posted Apr 12, 2009 at 11:21 AM | Permalink

          Re: Phil. (#108),

          Phil,

          SH ice extent Trend is increasing, but Temperature Trend goes the other way , from what you would intuitively think. Also stated by Steig et al.

          NH ice extent Trend is decreasing, and appears to line up with Temperature Trend.

          Any Thoughts on why?

    • Andrew
      Posted Mar 30, 2009 at 9:10 AM | Permalink

      Re: Nicolas Nierenberg (#15), Sea ice models have not done very well. If you were to compare the Arctic sea ice trend with the black line and gray fuzz since 1980, you would find that the models seriously under predict ice loss. On the other hand, if you do the same with Antarctic ice, you would find that the predicted decrease didn’t happen. Not withstanding Phil’s comments, which ironically use a George Will-esque type analysis, the trend in SH sea ice is pretty obvious:

      The real problem though is that in the arctic, the predicted sea ice trend for the century shows similar behavior to the predicted century trend in temperature, neither of which show the elevated temperatures of the 30’s and 40’s.

  12. Bob B
    Posted Mar 30, 2009 at 6:14 AM | Permalink

    Phil, SH sea ice:

    • Posted Mar 30, 2009 at 6:39 AM | Permalink

      Re: Bob B (#18),
      Yes the current cycle shows that both the maximum and minimum were slightly below the 1979-2000 mean.

  13. Arn Riewe
    Posted Mar 30, 2009 at 7:24 AM | Permalink

    Here’s and interesting site I picked up from a poster at WUWT:

    http://ocean.dmi.dk/arctic/meant80n.uk.php

    What’s interesting is the consistency and relatively short duration (~90 days) of summer temps at barely above freezing. This would seem to imply most melting comes from ocean heat transfer or radiation, not convective air melt. Anyway, it’s interesting stuff plotted on a year by year basis.

    • paminator
      Posted Mar 30, 2009 at 8:21 AM | Permalink

      Re: Arn Riewe (#21),

      Arn Riewe- excellent link! It is indeed interesting to see that air temperatures in 2007, for example, were not unusually warm compared with many other prior years. In fact, many prior years had integrated summer temperatures that were higher than 2007, yet sea ice minimum extent was much higher than in 2007.

      It appears to me as well that arctic air temperature currently has little to do with arctic sea ice extent.

  14. DeWitt Payne
    Posted Mar 30, 2009 at 9:01 AM | Permalink

    The first checkpoint for 2009 will be in mid-April. Will we see the big decrease in extent and area that happened in 2008? The 2009 Winter (Jan,Feb,Mar) seasonal average extent will be lower than 2003, 2004 and 2008, but well above 2005, 2006 and 2007. Uni-Hamburg still hasn’t posted their February data.

    • Posted Mar 30, 2009 at 3:30 PM | Permalink

      Re: DeWitt Payne (#25),

      The first checkpoint for 2009 will be in mid-April. Will we see the big decrease in extent and area that happened in 2008? The 2009 Winter (Jan,Feb,Mar) seasonal average extent will be lower than 2003, 2004 and 2008, but well above 2005, 2006 and 2007. Uni-Hamburg still hasn’t posted their February data.

      Over the last ~10 years mid April has been the time when the ice has all converged to about the same value (~12.5Mm^2 on May 1st) ready for the summer charge from June onwards.

      • Jedwards
        Posted Mar 30, 2009 at 11:17 PM | Permalink

        Re: Phil. (#54), Phil, did you really just ADMIT that there has been ZERO significant change in Sea ice over the last ten years????

  15. crashex
    Posted Mar 30, 2009 at 10:33 AM | Permalink

    I am also a devotee of the cryosphere today site, as well as CA, WUWT and Air Vent with daily visits to each. A common lurker that rarely comments.

    For other sea ice area devotees I’ll share an observation that I have already noted to Mr. Chapman. The total NH sea ice area anomoly plotted on Cryosphere Today does not equal the sum of the sea ice area anomolies for the 14 individual subregions. [Derivation of the results is left to the student]. I thought this would have been a simple check of the results reported, but the values don’t agree. A fairly consistent error of .2 to .3 is found, summer and winter. In all cases, the total NH anomoly is less than the sum of the subregions.

    Any takers on why such an anomoly anomoly exists? How long it may have existed, or whether or not it means anything?

  16. Andrew
    Posted Mar 30, 2009 at 12:26 PM | Permalink

    Phil. wants to be a smart arse by showing the non anomaly chart. Fine:

    We can play games like this, and show there is no “significant” Global Warming either.
    Now look at the anomaly chart again. Hard.

    I meant, BTW, where is the NH data going back to 1973? I see data back to 79 at CT but not 73…

    • Steve McIntyre
      Posted Mar 30, 2009 at 12:28 PM | Permalink

      Re: Andrew (#40), as I observed above, Phil used a chart from TAR which spliced something back to 1973 that wasn’t spliced in AR4. Where does the data come from? Dunno. Maybe Phil can locate it.

      • Posted Mar 30, 2009 at 12:45 PM | Permalink

        Re: Steve McIntyre (#41),

        I think it’s from the NSIDC in a multi-source dataset. “Merged ESMR, SMMR, and SSM/I Sea Ice Extent” I’ve never plotted it though because I thought I read somewhere it can’t be used for trend analysis.

        http://nsidc.org/data/smmr_ssmi_ancillary/area_extent.html

        Which has the statement.

        National Ice Center sea ice climatologies (Dedrick et al. 2001) were used, which were based on weekly operational sea ice charts. In the Southern Hemisphere, a weekly sea ice extent time series (Ropelewski 1983) from the U.S. National Ice Center was used. These supplemental data sets were also used to match or calibrate the three satellite-based products and eliminate biases between the products from the three sensors.

        • Steve McIntyre
          Posted Mar 30, 2009 at 12:55 PM | Permalink

          Re: Jeff Id (#43), Ref doesn’t go back to 1973. IPCC TAR spliced some other dataset with the satellite imagery. HArd to say how much hair is on the splice. To the extent that Phil’s argument relies on the spliced data, as it appears to do, then I’d expect Phil to come up with some basis for justifying the splice. Otherwise this TAR spitball is one that I’m not going to bother with.

      • Posted Mar 30, 2009 at 2:52 PM | Permalink

        Re: Steve McIntyre (#41),

        Where does the data come from? Dunno. Maybe Phil can locate it.

        Steve I gave the legend for the figure with the sources, a practice you would do well to follow incidentally.

        To the extent that Phil’s argument relies on the spliced data, as it appears to do,

        It doesn’t.

        Re: Andrew (#40),

        Phil. wants to be a smart arse by showing the non anomaly chart.

        On the contrary, plotting the monthly anomaly chart doesn’t tell you what you apparently think it does!
        Check out the following plot of antarctic sea ice area for the last year:

        Just from eye-balling the graph the integral of anomaly for the year is positive compared with the 1979-2000 mean, however the max and min for the year fall right on the 79-00 average. So no increase in ice (nor decrease) compared to the mean despite the positive anomaly, get it now?
        In fact it’s illustrative to compare the 1979 cycle with the 2008 cycle, from the min-max-min point of view they’re almost identical, however if you look at the anomaly plots they’re totally different! What this should tell you is that the monthly anomaly plot tells you very little about whether there’s any growth or decrease in the ice, it’s just showing differences in the way the ice grew/melted between the extremes. So if you want to show the growth in ice plot the proper quantity not the anomaly!
        Jeff says “Plotting max/min reduces the amount of available data”, but that extra data doesn’t say what you think it does.

        • Posted Mar 30, 2009 at 3:11 PM | Permalink

          Re: Phil. (#49),

          I’ll take the bait again, it’s better than working anyway.

          Ice anomaly represents the departure of average ice area from expected values. Therefore it seems to me that if you’re plotting trend, ‘anomaly’ is the correct value to use as seasonal variation in endpoints can be removed.

          It also gives an appropriate basis for establishing the significance of trend whereas the huge annual ice variation would make that impossible.

          Consider that if you measured only every march 3rd for a hundred years. Each March 3 the ice would increase or decrease by an measured amount. Certainly if your measurements were good, you could establish trend. Anomaly by removal of seasonal variation simply expands the process.

          In one version of gridded anomaly I calculated was actually daily! One point per day for 30 years. All the March 2’s, 3′,s 4’s together, putting the trends from all together results in a much better trend resolution than picking 12:00 on February 4 one time per year.

        • MrPete
          Posted Mar 30, 2009 at 3:19 PM | Permalink

          Re: Phil. (#49),

          What this should tell you is that the monthly anomaly plot tells you very little about whether there’s any growth or decrease in the ice, it’s just showing differences in the way the ice grew/melted between the extremes. So if you want to show the growth in ice plot the proper quantity not the anomaly!

          This raises a perhaps silly question.
          Seems to me that the amount of ice is a continuum. To that end, I ask:

          * Why should we care about the max and min values more than at any other time?
          * Wouldn’t the question of “growth” or “decrease” in a continuum be more validly measured based on the integral of the anomaly, rather than choosing one or two dates?

          In other words, why is it more valid to be concerned about the extent in March than in October? Why not consider the integral of all days in the year?

        • Steve McIntyre
          Posted Mar 30, 2009 at 6:04 PM | Permalink

          Re: Phil. (#49),

          I gave the legend for the figure with the sources, a practice you would do well to follow incidentally.

          Oh puh-leeze. Who else regularly provides retrieval scripts so that you can see where data comes from. I’ve noted the URL in #46, but that doesn’t entirely solve things. There wasn’t any AVHRR before late 1978. The question was – what was spliced with the AVHRR data prior to 1978. Quite possibly the URL explains a little, but presumably there was some reason why AR4 didn’t use the splice and perhaps you can explain this before you adduce data that IPCC did not use in their most recent report. I’m not saying that they shouldn’t have used this data – it’s not a topic that I’ve followed; you’re the one that introduced the obsolete graphic and I would appreciate a justification.

  17. Steve McIntyre
    Posted Mar 30, 2009 at 12:33 PM | Permalink

    Here is SH anomaly data to Feb 2009. This uses “area” which is what is used in AR4 Fig 10.13 (though they say that they use “extent”, they don’t: see the norms). The OLS trend in red.

    The trend using monthly data after allowing for autocorrelation, Santer-style, to my surprise and contrary to what I said above, is “significant” under a t-test allowing for AR1 autocorrelation (t=2.34)

    fm=lm(anom_SH~time,data=seaice);
    summary(fm)$coef
    # Estimate Std. Error t value Pr(>|t|)
    #(Intercept) -24.41816587 5.152416542 -4.739168 3.094819e-06
    #time 0.01224645 0.002583946 4.739439 3.090926e-06
    N=nrow(seaice)
    r=arima(fm$residuals,order=c(1,0,0))$coef[1] # 2.343225
    neff= N * (1-r)/(1+r) ;neff #90.48769
    summary(fm)$coef[2,"Std. Error"] # 0.002583946
    summary(fm)$coef[2,"Std. Error"] * sqrt( (N-2)/(neff-2)) # 0.005226324
    c(summary(fm)$coef[2,"t value"] ,fm$coef[2]/summary(fm)$coef[2,"Std. Error"]) #first principles expression for t-statistic
    # 4.739439 4.739439
    fm$coef[2]/ (summary(fm)$coef[2,"Std. Error"] * sqrt( (N-2)/(neff-2)) ) #first principles expression for t-statistic with neff
    # 2.343225

    I suspect that the “trend” is non-significant under some other measures that have been discussed here from time to time. As noted above, whether or not the trend is itself “significant”, it looks like the difference relative to models in the Santer sense of the Douglass debate is definitely significant.

  18. Posted Mar 30, 2009 at 1:03 PM | Permalink

    There are 3 datasets on the page. The third one supposedly goes back to 73.

    Daily and monthly sea ice extent summaries from 01 January 1972 to 31 December 2002 are provided for the Northern Hemisphere and 01 January 1973 to 31 December 2002 for the Southern Hemisphere.

    Can I ask where did your data come from? I only know of the gridded data for real time.

    • Steve McIntyre
      Posted Mar 30, 2009 at 1:20 PM | Permalink

      Re: Jeff Id (#45), Yep – ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/trends-climatologies/esmr-smmr-ssmi-merged/gsfc.nasateam.extent.1973-2002.s gives the TAR data.

    • Steve McIntyre
      Posted Mar 30, 2009 at 1:22 PM | Permalink

      Re: Jeff Id (#45), I posted this script last summar, but no harm in doing it again given how hard it is find things. I need to find a way of making these handy collation scripts more accessible.

      ##LOAD FRM NOAA 1979 to present
      #ftp://sidads.colorado.edu/DATASETS/NOAA/G02135
      #ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/Jun/N_200806_area.txt
      month1=as.character(1:12); y=nchar(month1);temp=(y<2);month1[temp]=paste(“0″,month1[temp],sep=””)
      month0=c(“Jan”, “Feb”, “Mar”, “Apr” ,”May” ,”Jun”, “Jul”, “Aug” ,”Sep”, “Oct” ,”Nov”, “Dec”)
      hemi=c(“N”,”S”)

      seaice=NULL
      for(j in 1:12) {
      for (k in 1:2) {
      url=”ftp://sidads.colorado.edu/DATASETS/NOAA/G02135″ #/Apr/N_04_area.txt”
      loc=file.path(url, month0[j],paste(hemi[k],”_”,month1[j],”_area.txt”,sep=””) )
      fred=readLines(loc)
      year=as.numeric(substr(fred,1,4))
      temp1=!is.na(year)&(year>=1978)
      fred=fred[temp1];year=year[temp1]
      test=data.frame(year, as.numeric(substr(fred,6,7)),substr(fred,27,27), as.numeric(substr(fred,29,34)),as.numeric(substr(fred,36,41)) )
      names(test)=c(“year”,”month”,”N”,”area”,”extent”)
      seaice=rbind(seaice,test)
      }
      }
      dim(seaice) #724 5 # 352 5

      order1=order(seaice$N,seaice$year,seaice$month)
      seaice=seaice[order1,]
      temp=(seaice$N==”N”)
      X=seaice[temp,]
      names(X)[4:5]=paste(names(X)[4:5],”N”,sep=”_”)
      X$area_S=seaice$area[!temp]
      X$extent_S=seaice$extent[!temp]
      X$time=round(X$year+(X$month-1)/12,2)
      N=nrow(X)
      X[1,]
      # year month N area_N extent_N area_S extent_S time
      #589 1978 11 N 12.02 8.95 16.4 11.56 1978.83

      time0=ts(seq(X$year[1]+(X$month[1]-1)/12, X$year[N]+(X$month[N]-1)/12,1/12),
      ,start=c(X$year[1],X$month[1]),end=c(X$year[N],X$month[N]),freq=12)
      seaice=data.frame(round(time0,2));names(seaice)=”time”
      test=match(seaice$time,X$time)
      temp=!is.na(test);sum(!temp) #2

      seaice$year=floor(seaice$time);
      seaice$month= 1+round( 12*(time0-seaice$year))
      seaice$area_N=NA;seaice$extent_N=NA;seaice$area_S=NA;seaice$extent_S=NA
      seaice[temp,4:7] = X[test[temp],4:7]
      #this copes with a couple of missing values in 1987-1988
      N=nrow(seaice)
      seaice[N,]
      #time year month area_N extent_N area_S extent_S
      #1 1978.83 1978 11 12.02 8.95 16.4 11.56

      # time year month area_N extent_N area_S extent_S
      #[1,] 1978.83 1978 1 4.30 2.78 2.42 1.30
      #[2,] 2009.08 2009 12 16.44 13.84 19.36 15.28

  19. Andrew
    Posted Mar 30, 2009 at 3:20 PM | Permalink

    :roll: There you go again…

  20. Bill Illis
    Posted Mar 30, 2009 at 6:45 PM | Permalink

    Actually, I think Phil’s SH numbers are pretty close but they are off a little.

    There is satellite data (monthly and daily) which goes back to 1972 for the Arctic and 1973 for the Antarctic.

    This is the monthly Southern Hemisphere sea ice extent anomaly from 1973 to current 2009.

    The data is here and I do not see a discontinuity in the data going from 1978 to 1979.

    ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/trends-climatologies/esmr-smmr-ssmi-merged/

    and here for the post-2002 data.

    ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/

    I want to thank NSIDC for making it so complicated to work with this data including putting the newer up-to-date data in an obscure GO2135 subdirectory along with 40 other GO___ subdirectories and then splitting all the data into monthly subdirectories (with an occasional month missing) just so you have to work really hard to use it and then showing all their data starting in 1979 when they have consistent data going back to 1972 and 1973.

    As you can tell, I think this organization goes out-of-their-way to prevent you from using all the data they have. Just go to their website and see if you can actually find anything to work with. I’ve never seen a website that says “look at all this data you can download” and then never actually takes you to any.

    • Posted Mar 30, 2009 at 7:09 PM | Permalink

      Re: Bill Illis (#56),

      I think this data is from a wide variety of sources, not just satellite. I haven’t looked around the NSIDC’s massive site for it today, the last time I did I read some references to the construction techniques. I think this is the reason trend sites doesn’t use this data. Nasateam and bootstrap ignore everything before 1979.

  21. vg
    Posted Mar 30, 2009 at 7:08 PM | Permalink

    I wonder why they (B Illis and Phil)have not put up data for ARCTIC ice from 1972….? Why was this data not posted by NCDC before? Are we bringing it out now to further hash/confuse the AGW? You know its going to look very very silly if temps keep going down and ice just stays normal for our lifetime…. I’m sure we won’t hear from them again (on any platform)LOL

  22. John F. Hultquist
    Posted Mar 30, 2009 at 7:32 PM | Permalink

    If you have the data they have-and-use it may be possible to show they make a few mistakes now and then. Wouldn’t want that, don’t you think?

  23. Bill Illis
    Posted Mar 30, 2009 at 7:34 PM | Permalink

    vg,

    I posted the Arctic sea ice data before.

    Here it is.

    Anomaly

    Some different years.

    And here is Arctic sea ice thickness from 1947 to 2008 for Alert and Eureka Canada which are the two most northerly communities in the world – nothing much to report: some ups, some downs, some recent decline potentially – (other than a few breaks, sea ice thickness has been measured once a week at these military and climate research bases – note this would be coastal sea ice versus polar pack ice – I’m sure if you go to the NSIDC website, they will say they have sea ice thickness data but you won’t actually find it).

  24. Bill Illis
    Posted Mar 30, 2009 at 7:56 PM | Permalink

    I should have posted this as well. There has been some research showing the Arctic sea ice extent is correlated with the AMO which has been rising since about 1975 (there could be a lag of a few years). The AMO seems to be trending down now so the Arctic sea ice could start to recover if the correlation continues.

    The SH sea ice data also correlates with southern ocean temperatures which peaked about 1975 and have been trending down (until very recently when they started going back up again). The southern atlantic and the northern atlantic seem to often go in opposite directions – they are important nodes of the Thermohaline Ocean Circulation.

  25. Posted Mar 30, 2009 at 10:22 PM | Permalink

    Steve # 55

    I have been doing some reconstructions of lunar images from the mid 1960’s and reconstructed the famous image of the Earth as seen from the Moon on August 23, 1966. This is contemporaneous with the Nimbus 1 images, though this one is in visible light. I have used an Earth political boundary overlay and “think” that I have identified the Antarctic ice pack for that year. If so, it is pretty big for that year.

  26. Posted Mar 30, 2009 at 10:23 PM | Permalink

    Here is the URL if this does not display.

    http://www.panoramio.com/photo/20640989

  27. AndyW
    Posted Mar 30, 2009 at 11:11 PM | Permalink

    I have to agree with Phil here, taking the anomaly constantly tells you more about how quickly or slowly the ice changes, it is the maxima and minima that are a better indicator, at least to me, on climate change.

    Indeed if you look at the graph

    the interesting point is not the change in maxima and minima, coz there ain’t any, over 30 years but an indication there may be a 6 or 7 year cycle within it.

    Arctic still above 14×106 kn2 as of today, following 2004 closely. Will be interesting to watch the dropoff as DeWitt said.

    Regards

    Andy

    • George DeBusk
      Posted Apr 1, 2009 at 8:57 AM | Permalink

      Re: AndyW (#64),

      I have followed the discussion about anomalies versus maxima and minima with interest. It seems to me there is interesting information in both data sets, and it could be telling different stories. The maxima and minima could respond to either sea temperature or air temperature, and is likely some function of both. It is possible that the high end of the extent curve is more likely to be controlled by sea temperature, since the greater thermal mass of the sea means it is less likely to show rapid changes at the point where the sea is too warm to freeze (absent some shift in circulation, of course). The anomaly, on the other hand, seems to me more likely to respond to air temperature changes, as the areas where the sea is cold enough for sea ice to form would freeze quicker if the air temperature was lower. Of course if the greatest extent of sea ice is controlled by some land or water mass barrier, you might see a strong response in the anomalies but little or no response at the upper end of sea ice extent.

      Of course the converse could be true if there were some significant change in ocean circulation, as seems to have happened in the 1990s and early 2000s in the North Atlantic. If a warm water mass moves into a formerly cold area of sea, both the maximum and minimum extent as well as the anomaly would decrease even if air temperature was constant (or possibly even if it decreased).

      • AndyW35
        Posted Apr 2, 2009 at 12:36 AM | Permalink

        Re: George DeBusk (#79),

        I’d agree with that in general George. I did recall seeing SST’s for 2008 and 2009 from Phil on the other previous thread that showed SST’s this year are higher than last, though the ice extent is similar. It’s an interesting topic, could do perhaps with some input with an expert in the field to give us all guidance.

        As the professionals use both maxima/minima and averages I would guess both have their merits.

        Regards
        Andy

  28. VG
    Posted Mar 31, 2009 at 12:06 AM | Permalink

    # 60 Bill Illis Thanks for those graphs I had not known that they had been posted before. I still think Will’s statement that global ice = normal is re-inforced even more by the recent data. However we shall see hoe NH ice melts this yera. My prediction = way less than previous last 2 years.

  29. AndyW
    Posted Mar 31, 2009 at 3:17 AM | Permalink

    There’s quite a few people predicting a lot higher ice extent minima for this summer now so it will be interesting to see what transpires.

    I actually think it is unlikely to be much higher than 2008 and there is a possibility it might be lower. I don’t see it getting back to the good all days at all this year.

    Regards

    Andy

  30. Robinedwards
    Posted Mar 31, 2009 at 9:50 AM | Permalink

    I’ve been admiring the graphics referenced by Bill Illis and AndyW in posts 56,60,61 and 64. However, what would be really much more informative from my point of view would be the actual numbers that were used to generate the graphs. Does anyone know where they might be found?

    It is usually much handier to have access to the values themselves, not the anomalies from some (arbitrary) base values that someone else has chosen. The calculations to generate anomalies are surely rather trivial and the operation detracts unnecessarily from the information content of the data, I feel.

    Can someone explain why climate data are so often reported as “anomalies”? I regard an “Anomaly” as something strange and unexpected. In climate there are no anomalies, merely observations of an existing state of affairs. You either accept the value or come up with an adequate reason to support your contention that it is an anomaly. This has been done before, I am pretty sure!

    Robin

  31. AndyW35
    Posted Mar 31, 2009 at 12:48 PM | Permalink

    Hi Robin,

    My linked graph is not an anomaly gtaph, it is the actual area graph.

    Regards

    Andy

  32. Robinedwards
    Posted Mar 31, 2009 at 1:33 PM | Permalink

    Thanks, Andy,

    For your graph I can see that the data are clearly monthly, and are actual ice extents, but Bill’s use the letters ANOMAL in their names!

    Do you know where the numerical data are to be found? This would be very intriguing for me, because I use a non-standard analytical technique that sometimes enable me to spot things that others seem to have overlooked. At least, I think so!

    Robin

  33. Posted Mar 31, 2009 at 2:22 PM | Permalink

    I have a 50 Euro sea ice bet started at RC and continued at Lucia’s blog that 2009 sea ice minimum extent will stay above 4.01 Million Square Kilometers (the 2005 low) as reported here: http://arctic.atmos.uiuc.edu/cryosphere/iphone/iphone.currentarea.series.html

    Lost the same bet last year, assuming Arctic melting was being exaggerated and there would be enough reversion to the mean to make a it a good bet. Unfortunately I didn’t realize how the likely thinning of old ice and other factors would tend to mean reversion to the mean could take several years.

    Am I going to win this year?

  34. sean
    Posted Mar 31, 2009 at 2:57 PM | Permalink

    Phil,

    I think I see your point regarding anomalies, if they are being used to compare particular days. If we just look at the anomalies for June 1, for example, the data will tell us more about the timing of the ice melt each year than it will about the amount of ice that year.

    But if you average the total ice area (or extent) for every day of a whole year, that annual average should, it would seem, tell you more about the total quantum of ice that year than a simple average of the max and min. And the anomaly of that annual average vs. the mean for all years should be the same as the average of all the anomalies of all the days in that year, shouldn’t it?

    • pjm
      Posted Mar 31, 2009 at 9:28 PM | Permalink

      Re: sean (#73), imagine, for the sake of argument, that the ice extent is the same every 1st January and every 1 July. Further, imagine that the actual max and min are also the same over the time period. The ice can still melt later and freeze earlier, increasing your average. This would be an interesting change, and possibly indicate something important, but I would not equate it to an increase in ice extent over the time period.

      • Dale S
        Posted Mar 31, 2009 at 10:38 PM | Permalink

        Re: pjm (#74), imagine, for the sake of argument, that you’re considering the ice area in a backyard pool in Chicago. It’s frozen over completely every winter, and melts completely every summer. Would an average of ice max and ice min be a useful measure of ice area over the course of the year?

        If one year the pool froze over in September and melted in early May, while the next year the pool froze over in November and melted in early March, both years still have the same maximum and the same minimum. But the first year clearly had more ice than the second year.

        It’s not clear to me why comparing maximum and minimum ice area is more useful or interesting than how much ice there was over the course of the year.

        • AndyW35
          Posted Apr 1, 2009 at 1:04 AM | Permalink

          Re: Dale S (#75),

          But the Artic and Antartic do not melt totally, nor freeze totally so your analogy falls short in this regard.

          Regards

          Andy

        • Dale S
          Posted Apr 1, 2009 at 7:55 AM | Permalink

          Re: AndyW35 (#77),
          I agree it’s not a perfect analogy. But its imperfection doesn’t explain to me what makes min/max more useful, interesting, and/or important than a daily average. If you had more sea ice for 90% of the year, but ended up with a smaller minimum area, did you really have less ice? Does it really only matter if the ice melts, and not at all when it melts?

          Another stupid question — doesn’t the Artic Ocean freeze totally in the winter? At maximum extent, how much of the Artic Ocean is left unfrozen, and at minimum extent how much artic sea ice is actually outside the Artic ocean?

        • DeWitt Payne
          Posted Apr 1, 2009 at 9:34 AM | Permalink

          Re: Dale S (#78),

          Another stupid question — doesn’t the Artic Ocean freeze totally in the winter? At maximum extent, how much of the Artic Ocean is left unfrozen, and at minimum extent how much artic sea ice is actually outside the Artic ocean?

          Cryosphere Today has all that data in graphical form. You can click on a colored region on the map in the Latest regional sea ice area and anomalies section or on the name of the area and see the area and anomaly data for the past year or so. But the answer to your questions is yes, although the ice concentration is not 100% everywhere, and not much.

  35. Andrew
    Posted Mar 31, 2009 at 11:08 PM | Permalink

    These might interest folks:

  36. DeWitt Payne
    Posted Apr 1, 2009 at 9:26 AM | Permalink

    Here is a 365 day moving average plot of Arctic Ice Extent from JAXA data:

    The seasonal averages are also interesting. Here is the Winter (Jan, Feb, Mar) Arctic Ice Extent including the latest JAXA data

  37. sean
    Posted Apr 1, 2009 at 10:32 AM | Permalink

    Here’s a few more thoughts on the debate over anomalies vs. the average of the max and min extent.

    1. When we talk about annual mean global temperature, we talk about the average of all the days in the year, I believe, rather than the average of the hottest and coolest day in the year.

    2. The reason that the climate community talks about sea ice is that it is connected with changes in global temperature. Thus if sea ice declines dramatically, it is seen as confirmation of global warming.

    3. I would imagine that the sea ice statistic with the highest correlation to mean global temperature is average annual sea ice extent. Therefore, this statistic should be most relevant to the debate over whether sea ice confirms or does not confirm global warming. I realize that complex ocean currents will strain the relationship between global sea ice and global temperature, but I don’t see why the correlation between other sea ice statistic and global mean temperature wouldn’t suffer even more from the complexity of ocean currents.

    4. Other sea ice statistics may be relevant to understanding the effects of global warming. For example, regardless of the annual average extent, if the Arctic ice minimum is heading toward zero that will have implications for the polar bear population.

    6. It may be that the climate models predict more vlatility in ocean currents with higher temperatures, but (a) if that is the case, the same presumably should be true of wind currents and therefore one could argue that the average of the hottest and coolest days in the year is more relevant than the annual average of all the days; and (b) it would seem that the average global temperature of the ocean would have to be higher to cause this effect, and if the average sea temperature is higher over the course of the year, and the average ground temperature is higher over the course of the year, then the average sea ice extent of all the days in the year should be lower.

    7. Saying that lower annual sea ice extent may simply be a result of the ice melt beginning earlier and lasting longer is like saying that higher annual global mean temperatures may be the result of spring and summer coming sooner and lasting longer. Wouldn’t that be seen as confirmation of global warming?

    These are just a few thoughts. I am not a scientist and so you can take these thoughts as questions.

  38. MikeP
    Posted Apr 2, 2009 at 12:23 PM | Permalink

    Changes in the minimum ice extent have been used as a “confirmation” of global warming. However, any connection will (at least in part) be indirect. The 2007 summer minimum is an example of this. Increased melting was due to increased flushing of ice into the N. Atlantic where it then melted. It may well be that the changed circulation patterns were themselves induced by global warming.

    Those who espouse global warming as the primary driver, then predicted that 2008 would have a lower minimum. This was based on an expectation that the 2008 melt would be enhanced by increased first year ice (a tipping point where less summer ice each year would make melting the following year easier and lead to an ice free summer arctic).

    In fact, the circulation patterns did not reappear. However there was increased melt at the height of the season which may have been due to the first year ice. That’s why this next summer will be quite interesting. Will the 2009 minimum be greater than 2008, continuing a trend back toward 2003-2006? Or will it be lower, giving more credence to the warmers?

    Since the magnitude of the maxima and minima depend to a significant degree on indirect effects related to winds and currents, I believe that these may be critically flawed measures of global temperature changes. I personally think that average values are less sensitive to weather patterns that may set up and persist over a season. Although persistent weather and wind patterns are coupled with longer term climate changes, the exact pattern seems to depend on more subtle details such as whether or not one is coming out of a La Nina, how strong it has been, and on and on. Thus the effects on maximum and minimum ice should also be dependent on more subtle climate details.

  39. Flanagan
    Posted Apr 3, 2009 at 12:27 AM | Permalink

    Mike:

    let me remind you that no model at all predicted that Arctic sea ice would disappear in 2007 or 2008, etc. The average date for no Arctic sea ice in the summer is around 2030-2040. The rest of the “predictions” is based on nothing but the desire to attract media attention.

  40. mundus
    Posted Apr 3, 2009 at 6:15 AM | Permalink

    There is an new paper published today by GRL: Wang et Overland (2009), “A free ice summer Arctic within 30 years?”. Notice the question mark in the title! In the abstract they say:

    “Using the observed 2007/2008 September sea ice extents as a starting point, we predict an expected value for a nearly sea ice free Arctic in September by the year 2037. The first quartile of the distribution for the timing of September sea ice loss will be reached by 2028.”

    Of cause, this paper is based on model-projections. From the abstract:

    “Our analysis is based on projections from six IPCC models, selected subject to an observational constraints. Uncertainty in the timing of a sea ice free Arctic in September is determined based on both within‐model contributions from natural variability and between‐model differences.”

    Maybe it is worth to be audited here at CA.

  41. mundus
    Posted Apr 3, 2009 at 6:26 AM | Permalink

    Correction: The title of this paper is: “A sea ice free summer Arctic within 30 years?” Sorry for the mistake.

  42. Follow the Money
    Posted Apr 3, 2009 at 12:42 PM | Permalink

    Changes in the minimum ice extent have been used as a “confirmation” of global warming.

    Do they support this with concurrent temp readings in the region? I have never seen that. Maybe a couple of times with some “red” coloration, but how much temp increase does that really signify, and would it be enough to explain the phenomenon.

  43. BarryW
    Posted Apr 3, 2009 at 3:01 PM | Permalink

    Wow, walk out of the room for a few days and find there’s been a bar fight going on while you were gone.

    Re: DeWitt Payne (#80),

    The troubling thing about your second graph is how every one of the sources are consistent with each other except for CT. Something seems to have changed in the data or algorithms about 2006. Does summer show the same pattern?

    • DeWitt Payne
      Posted Apr 3, 2009 at 8:34 PM | Permalink

      Re: BarryW (#89),

      Does summer show the same pattern?

      Funny you should ask that. Yes. So do Spring and Fall. I’ve pointed this out to William Chapman at Cryosphere Today and got more or less brushed off. At least he did reply. I keep meaning to write a guest post for the Jeff’s, but I’m incredibly lazy and writing is way too much like work. So here are some results. My favorite is the difference plot of Cryosphere Today and NSIDC. To be comparable with CT historical practice, only mid month data was used to calculate the NSIDC averages. NSIDC extent was not affected by the pole hole problem. Ideally, there should be a constant difference with some scatter. No such luck.

      I’ll just link the rest.

      Spring

      Summer

      Fall

      The other thing to note is that if Cryosphere Today is correct and everyone else is wrong, average ice concentration has gone up as area has dropped. I have those plots too, but the CT data is synthetic, based on transforming Uni-Hamburg data, so they’re less probative.

      • BarryW
        Posted Apr 3, 2009 at 10:21 PM | Permalink

        Re: DeWitt Payne (#90),

        Wow, thanks DeWitt. Unless Chapman has a rigorous explanation of the discrepancy he should be ashamed of his organization’s lack of quality control. If I saw all of the other groups that provide data diverging from my output I would certainly be trying to find out what was wrong instead of brushing people off.

  44. Mike Bryant
    Posted Apr 3, 2009 at 10:06 PM | Permalink

    CT is a joke… Thanks for making it abundantly clear, DeWitt.
    Mike

    • DeWitt Payne
      Posted Apr 4, 2009 at 12:41 PM | Permalink

      Re: Mike Bryant (#91),

      CT is a joke…

      I don’t have a problem with CT’s ice area data for the NH and SH. That continues to be in agreement with the other sources, particularly Uni-Hamburg. That is the data can be transformed from one to the other linearly. CT didn’t have to correct their area data from late 2008 and early 2009 like NSIDC. It does surprise me that they have ignored the discrepancy in their extent data even when I brought it to their attention. The seasonal extent plot would look less scary, but it’s bad enough without the exaggeration. I gather that CT is not Chapman’s primary responsibility so he may not have much time to spend looking at old data.

      The brownie bet was based on the posted data at CT. It didn’t matter if the data didn’t agree with other sources. Or at least that was the thinking at the time.

  45. Mike Bryant
    Posted Apr 3, 2009 at 10:12 PM | Permalink

    DeWitt,
    How would this affect Lucia’s brownie contest? She might have to make more brownies…

  46. Mike Bryant
    Posted Apr 4, 2009 at 1:00 PM | Permalink

    DeWitt,
    If he doesn’t have time to correct obvious mistakes, perhaps he should take the site down.
    Mike

  47. AndyW
    Posted Apr 5, 2009 at 11:02 PM | Permalink

    Does CT have a different % concentration cutoff for extent that might explain the difference?

    Regards

    Andy

    • DeWitt Payne
      Posted Apr 6, 2009 at 8:26 AM | Permalink

      Re: AndyW (#96),

      I don’t see how a different cutoff would produce step changes from year to year. For every other data set, a linear transform (y=mx+b) gives an excellent fit between different data sets.

      Remember this is just one graph on a page filled with other graphs and images. Ice area appears to be the primary mission of the site and I don’t have a problem with their area data.

  48. Jordan
    Posted Apr 6, 2009 at 1:31 PM | Permalink

    Quite a lot of comment and setting of expecations here at Science Daily.

    Any thoughts on the strength of these comments:

    Until recent years, measurements have shown most Arctic ice has survived at least one summer and often several, said Meier. But the balance has now flipped, and seasonal ice — which melts and re-freezes every year — now comprises about 70 percent of Arctic sea ice in winter, up from 40 to 50 percent in the 1980s and 1990s, he said. Thicker ice that has survived two or more years now comprises just 10 percent of ice cover, down from 30 to 40 percent in years past.

    In a related study led by Ron Kwok of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., researchers have demonstrated a way to estimate ice thickness over the entire Arctic Ocean. Using two years of data from NASA’s Ice, Cloud and Land Elevation Satellite, or ICESat, the team made the first basin-wide estimate of the thickness and volume of the Arctic Ocean ice cover for 2005 and 2006.

    “Heading into the 2009 summer melt season, the potential continues for extensive ice retreat due to the trend toward younger, thinner ice that has accelerated in recent years,” said Maslanik, also a member of the Cooperative Institute for Research in Environmental Sciences. “A key question will be whether this second year ice is thick enough to survive summer melt,” said Maslanik.

    “If it does, this might start a trend toward recovery of the perennial sea ice pack,” Maslanik said. “If it doesn’t, then this would be further evidence of the difficulty of re-establishing the ice conditions that were typical of 20 or 30 years ago.”

  49. AndyW35
    Posted Apr 6, 2009 at 1:52 PM | Permalink

    Interesting update from NSIDC today

    http://nsidc.org/arcticseaicenews/

    Regards

    Andy

  50. Mike Bryant
    Posted Apr 6, 2009 at 3:12 PM | Permalink

    According to the NSIDC update:

    “Sea ice extent averaged over the month of March 2009 was 15.16 million square kilometers…”
    That seems rather odd since the graph appears to be less than that. Also, I wonder what the highest 2009 NH sea ice extent was.
    In comments here:

    http://www.climateaudit.org/?p=3463

    I guessed 15.5 million square kilometers…

    “A key question will be whether this second year ice is thick enough to survive summer melt, if it does, this might start a trend toward recovery of the perennial sea ice pack,” Maslanik said.

    I find it interesting that we are starting to see escape clauses being uttered here. Maybe they know something about a suspected turnaround that we don’t.

    • bender
      Posted Apr 7, 2009 at 8:31 AM | Permalink

      Re: Mike Bryant (#100),

      we are starting to see escape clauses being uttered here

      1. “Escape clause?” Hardly. Is it that unreasonable to suppose there might be some natural internal variability around the trend in declining sea ice extent? When you refer to “suspected turnaround” it seems you may be over-interpreting the word “recovery”.
      .
      2. Who, in your mind, are these “utterers” that are “starting” to change “their” message? Sure, alarmists may tend to ignore trend uncertainty associated with natural variability. That doesn’t mean that everyone does. And the most credible of statistical climatologists certainly do not. Maybe no one is changing their message and you are just starting to hear from different kinds of sources?

  51. AndyW
    Posted Apr 6, 2009 at 10:55 PM | Permalink

    They still sounded very bullish on the whole to me Mike.

    Looking at those temps and the lack of multiyear ice I wonder if we will see the North East passage open again this year for the 2nd year on the trott? Does anyone know the last time that happened?

    Regards
    Andy

  52. Mike Bryant
    Posted Apr 7, 2009 at 9:22 AM | Permalink

    Bender,
    As is so often the case, you may very well be right. I will sleep on it…
    Mike

  53. Chris
    Posted Apr 7, 2009 at 10:46 AM | Permalink

    has/had been declining, may still be

  54. Chris
    Posted Apr 8, 2009 at 6:24 AM | Permalink

    #110 “the NH and the Arctic in particular, are anything but “cooling””

    This implies they are warming. Justification?

    I suggest both are on a cooling trend since 2005, albeit from a particularly high starting point. On certain measures the cooling remains quite pronounced e.g. NH SST anomalies for Feb 2009 at +0.213C were ~identical to those of Feb 2008 (+0.212), comparable with pre-Pinatubo Feb 1990 (+0.152) and 1991 (+0.186), and incidentally lower than the SH SST anomalies for Feb 2009 (+0.230C)

    http://www.cru.uea.ac.uk/cru/data/temperature/hadsst2nh.txt

    http://www.cru.uea.ac.uk/cru/data/temperature/hadsst2sh.txt

    RSS has Feb/Mar 2009 in the ~Arctic i.e. 60-82.5N (-0.51C anomaly) as the coldest Feb/Mar since 1987.

    http://www.remss.com/data/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_2.txt

    NH Snow cover anomalies have now overtaken last year’s and were ~2 million km2 greater for March 2009 than for March 2008.

    http://climate.rutgers.edu/snowcover/table_area.php?ui_set=1&ui_sort=0

    Meanwhile the lowest trending AMO since 1994 (alongside the continued low PDO index) suggests the last couple of years might not be such a good indicator of what will happen to NH/Arctic temps this summer?

    http://www.cdc.noaa.gov/data/correlation/amon.us.long.data

    • AndyW35
      Posted Apr 8, 2009 at 10:41 AM | Permalink

      Re: Chris (#115),

      Chris,

      Thanks for adding value to the debate by clearing up benders misconception and misinformation.Thanks again for supporting your claims with data.

      Regards

      Andy

  55. Mike Bryant
    Posted Apr 8, 2009 at 11:20 AM | Permalink

    “1. “Escape clause?” Hardly. Is it that unreasonable to suppose there might be some natural internal variability around the trend in declining sea ice extent?”

    Well, Maslanik said. “A key question will be whether this second year ice is thick enough to survive summer melt, if it does, this might start a trend toward recovery of the perennial sea ice pack,”

    A “…trend toward recovery of the perennial sea ice pack,” is not the same thing as “…natural internal variability around the trend in declining sea ice extent?”.

    I submit that the utterer, Maslanik’s words left some room for doubt about the direction of the trend after this summer’s melt. Apparently Meier didn’t like his quote since it was left out of the press release here:

    http://nsidc.org/arcticseaicenews/

    So, you are correct, I am hearing from someone I haven’t heard from before, Maslanik. And Maslanik apparently felt it necessary to mention this “way out” of the more “bullish” predictions of Meier.

  56. BarryW
    Posted Apr 10, 2009 at 9:06 AM | Permalink

    JAXA Arctic extent on 4-10-2009

     
    year           extent       weekly change
    2003         14.06687            -0.18359
    2004         13.58984            -0.29219
    2005         13.37000            -0.12422
    2006         13.03297            -0.27875
    2007         13.24547            -0.18484
    2008         13.91266            -0.16219
    2009         13.74828            -0.19219

  57. DeWitt Payne
    Posted Apr 10, 2009 at 9:49 AM | Permalink

    Uni-Hamburg has updated their Arctic and Antarctic AMSR-E ice area and extent data through 4/1/2009.

    Average Arctic ice concentration has increased the last few days. Global sea ice is also increasing faster than the recent average, although it is still below the 2008 level for this date. At about this time last year, there was an increase in the rate of loss of Arctic ice extent to well above the recent average. It will be interesting to see if 2009 repeats this pattern.

  58. Mike Bryant
    Posted Apr 12, 2009 at 8:23 AM | Permalink

    How fast is the Arctic Sea Ice decline?

    http://noconsensus.wordpress.com/2009/04/10/how-fast-is-arctic-sea-ice-declining/

  59. AndyW35
    Posted Apr 12, 2009 at 9:03 AM | Permalink

    Thanks Mike for that post, something to read when I am back at work I think rather than Easter weekend when I am sneaking posts in whilst spending time with my family.

    Have to say at this point I am getting rather unhappy with WUWT posts on the Artic. Unlike this thread, where the trends are observed and commented on, it does seem they are getting posts pushing an agenda mainly. It’s putting the cart before the horse.

    The last thread published by Steve Goddard is a good example of it. Winter results are being pushed as evidence that the summer will see a large rebound on the value of minimal extent.To me that’s silly. I’d rather just see what happens. We have our guesses here, and they are just guesses, but they seem to want to paint their guesses with their own agenda :(.

    I’d rather just watch it and then see what the scientists come up with to explain the data and also why they were accurate or inaccurate as they were in 2008.

    Regards

    Andy

  60. Posted Apr 12, 2009 at 11:14 AM | Permalink

    DeWitt Payne:
    April 10th, 2009 at 9:49 am
    Uni-Hamburg has updated their Arctic and Antarctic AMSR-E ice area and extent data through 4/1/2009.
    Average Arctic ice concentration has increased the last few days. Global sea ice is also increasing faster than the recent average, although it is still below the 2008 level for this date. At about this time last year, there was an increase in the rate of loss of Arctic ice extent to well above the recent average. It will be interesting to see if 2009 repeats this pattern.

    I would think it’s almost certain, round about now the Bering ice starts to recede rapidly which is the major contributor the drop in ice coverage at this time of year. Baffin also starts about now but is slower but ultimately contributes more. This year about 0.3Mm^2 of the Bering ice is only a couple of weeks old so once it starts melting it’ll go fast. That’s why there’s four ‘seasons’ when you talk about the variability of the Arctic ice cover: Nov.-Jan refreeze without much variability, late April-July thaw without much variability, Jan-April a lot of variability which depends on the fringes and extra-Arctic ocean ice, July-Nov variability due to what happens to multiyear ice. My main point is that there isn’t much connection between the periods of variability, what happens in the summer isn’t dependent on whether the Bering ice starts to melt next week or last. On July 1st the extent (AMSR) will be ~9.5-10 Mm^2 then the end run will start which will depend on things like how much multiyear ice left via the Fram since last fall etc.

    • DeWitt Payne
      Posted Apr 12, 2009 at 9:03 PM | Permalink

      Re: Phil. (#122),

      The OLS trend for JAXA July 1 Arctic extent has a slope of -120,000 km2/year. So 9.5 to 10.0 Mm2 on 7/1/2009 would be considerably above this trend (projected value ~9.1 Mm2) and way above the 9.2 and 9.3 Mm2 recorded in 2006 and 2007. Bering Sea ice will have little effect on this value because it’s always gone by 7/1 anyway.

      • Posted Apr 13, 2009 at 12:16 AM | Permalink

        Re: DeWitt Payne (#125),

        The OLS trend for JAXA July 1 Arctic extent has a slope of -120,000 km2/year. So 9.5 to 10.0 Mm2 on 7/1/2009 would be considerably above this trend (projected value ~9.1 Mm2) and way above the 9.2 and 9.3 Mm2 recorded in 2006 and 2007. Bering Sea ice will have little effect on this value because it’s always gone by 7/1 anyway.

        Yeah but what’s the confidence interval? I’d just eyeballed the range, ~9.2Mm^2 is OK for the bottom bound. The reference to Bering was that it would likely be responsible for a sharp drop like last year. Either way the main point is that 2nd ‘melt season’ starts in July in a fairly well defined range, irrespective of what happens now.

        • DeWitt Payne
          Posted Apr 13, 2009 at 9:45 AM | Permalink

          Re: Phil. (#126),

          Yeah but what’s the confidence interval? I’d just eyeballed the range, ~9.2Mm^2 is OK for the bottom bound.

          The mean is 9.7 Mm2 and the SD is 0.34. Prediction intervals are seriously dicey given the small number of data points and the likely autocorrelation. A 2 SD range is 9.1 to 10.4 Mm2. Then add the linear trend and you get something like 8.4 to 9.8 Mm2. But I think your guess is probably going to be correct. The 7/1 extent will be close to the mean and the magnitude of the apparent recent trend will be reduced.

  61. Mike Bryant
    Posted Apr 12, 2009 at 12:26 PM | Permalink

    Andy, “We have our guesses here, and they are just guesses, but they seem to want to paint their guesses with their own agenda :(.” I understand how you feel. I also understand why someone might want to push an opposing view, especially when NSIDC focuses so completely on NH ice, only mentioning the Antarctic when a piece of an ice shelf breaks off. Why won’t they show the same picture of the Antarctic and the historic ice edges as they do the Arctic in their news releases? This seems to leave them open to charges of propaganda and invites the type of posts that you see at WUWT.

    • Posted Apr 13, 2009 at 8:22 AM | Permalink

      Re: Mike Bryant (#124),

      I also understand why someone might want to push an opposing view, especially when NSIDC focuses so completely on NH ice, only mentioning the Antarctic when a piece of an ice shelf breaks off. Why won’t they show the same picture of the Antarctic and the historic ice edges as they do the Arctic in their news releases? This seems to leave them open to charges of propaganda and invites the type of posts that you see at WUWT.

      Why do you expect the NSIDC to give the same prominence the Antarctic as the Arctic, the N stands for ‘National’ and the US has a coastline in the Arctic ocean? Check out Environment Canada’s website, there’s extensive coverage of the Arctic but no mention of the Antarctic, do you have a problem with that too?
      http://ice-glaces.ec.gc.ca/
      The Japanese have a website which gives Arctic SST and Sea ice maps but no corresponding Antarctic maps.

      http://sharaku.eorc.jaxa.jp/AMSR/index.html

      It’s not unreasonable to give more prominence to what’s happening in one’s own backyard, I assume the Aussies are more interested in the Antarctic?
      This in no way excuses the nonsense that Goddard in particular posts on WUWT.

  62. AndyW35
    Posted Apr 13, 2009 at 1:23 AM | Permalink

    All 3 years with high values at this time on the JAXA graph show large drop offs about now, unlike the 3 lower, so it’s highly likely that this year will not follow suit, indeed the first indications or it turning the corner are just shown. Nobody expects it not to be following the crowd in the May to June slot are they?

    Looking at

    The first signs of wear and tear have now appeared around Svarlbad. Labrador sea and Baffin bay seem to be pretty “yellow” as well although the Baring sea seems to be better than last year at this time if memory serves me correctly, perhaps due to the cold sea temps? This is where people hammer with contradictory data showing how bad my memory is :D

    Good point Mike #124. I don’t know why NSIDC is always quite so bullish, then again I think WUWT goes too far the other way to try and make amends. What happened to the good old days of trying to be scientifically neutral whilst smoking a pipe and stroking beards in a thoughtful manner?

    Mind you only my wife smokes a pipe and strokes her beard in my household.

    Regards

    Andy

    • Posted Apr 13, 2009 at 8:33 AM | Permalink

      Re: AndyW35 (#127),

      All 3 years with high values at this time on the JAXA graph show large drop offs about now, unlike the 3 lower, so it’s highly likely that this year will not follow suit, indeed the first indications or it turning the corner are just shown. Nobody expects it not to be following the crowd in the May to June slot are they?

      Yes and at first glance these are years with more extensive ice in the Bering sea which melts very rapidly at this time of year, hence my comments above.

  63. Shawn Whelan
    Posted Apr 13, 2009 at 7:47 AM | Permalink

    The science has become more politics than science. Truly unfortunate.

    Unless there is some freak warmth like 2007 (and that is very unlikely)expect to see another increase in minimum ice levels in the Arctic.

    When the PDO has cooled in the past the ice has increased. History will repeat.

    • Posted Apr 13, 2009 at 8:41 AM | Permalink

      Re: Shawn Whelan (#128),

      When the PDO has cooled in the past the ice has increased. History will repeat.

      The ‘Cooling’ phase of the PDO is so named because of its effect on the Pacific NW coast of N America, as shown below this is not true of the Bering Sea and Western Arctic ocean.

  64. Mike Bryant
    Posted Apr 13, 2009 at 8:53 AM | Permalink

    Phil.
    All good points. I always appreciate your obvious mastery of the subject of sea ice, still I wish that NSIDC wasn’t obviously so biased particularly in the PR releases. I believe that in the long run they are only hurting their own credibility. There is just as much interest in Antarctica as there is in the Arctic. Is Steig still down there?

  65. AndyW35
    Posted Apr 13, 2009 at 1:26 PM | Permalink

    Oops

    ” so it’s highly likely that this year will not follow suit, indeed the first indications or it turning the corner are just shown.”

    should read

    ” so it’s highly likely that this year will follow suit, indeed the first indications or it turning the corner are just shown”

    Good job I’m not a scientist posting on a government site. :)

    Regards

    Andy

    • DeWitt Payne
      Posted Apr 15, 2009 at 9:08 AM | Permalink

      Re: AndyW35 (#134),

      so it’s highly likely that this year will follow suit, indeed the first indications or it turning the corner are just shown

      Not yet. Today’s JAXA extent data was slightly higher than yesterday
      4/13/2009 13644688
      4/14/2009 13653281 8593

      compare to 2008
      4/12/2008 13768125
      4/12/2008 13712969 -55156

      2009 has seriously closed the gap with 2003 and 2008. It’s down to less than 100,000 km2. The smoothed rate is way above the 2003 to 2007 average. Unless the melting picks up steam in the next few days (and the odds are that it will), we could see a new daily high in the JAXA extent data.

  66. Shawn Whelan
    Posted Apr 14, 2009 at 8:30 AM | Permalink

    Phil
    The ‘Cooling’ phase of the PDO is so named because of its effect on the Pacific NW coast of N America, as shown below this is not true of the Bering Sea and Western Arctic ocean.
    Whatever. I stand by my prediction that the ice will increase this year.

    What do you predict?

  67. mark in austin
    Posted Apr 15, 2009 at 8:16 AM | Permalink

    so GISS is in and it was the coldest march since 2000 and colder than 1990 i believe. interesting to be sure! only one month, but it seems like we may experience some more cooling. particularly because over the past 30 years only a few months had a warmer april than march. in MOST cases (85%?) April came in cooler…

  68. Keith
    Posted Apr 15, 2009 at 1:26 PM | Permalink

    This may be off topic here, if so, Steve please move this to Unthreaded. But I think I have found something interesting about the Catlin Ice Team.

    For those of us who have been following the tumult that has been plaguing the Catlin Ice Exploration team, I provide something new. I have also posted this over on WUWT, but I think it needs to be shared here.

    For those who are new, the Catlin Ice Team of three explorers are endeavoring to reach the North pole, while measuring the thickness and decline of the Arctic ice. They chose an unusual start point of 80 140W, requiring a plane drop them off on the Arctic ice sheet. The Team had been beset by technical problems, severe cold, and it was discovered that their website was publishing old biotelemetric data as live. They just released an early report on the ice thicknesses they have measured, lamenting that all the ice they are finding is thin first year ice that will probably melt this year. But I have found a flaw in their report! They are not in the location they are showing in the report.

    If you compare the image they provide here
    ( http://www.catlinarcticsurvey.com/assets/downloads/Ice_Report_14_4_09.pdf ) with the image from the route page ( http://www.catlinarcticsurvey.com/assets/downloads/RouteMap.pdf ), you can see the error.

    The grid lines on the findings page are for every five degrees of longitude and latitude. On the Route page, the longitude line are for every ten degrees. Now, the initial start point of the Ice team was supposed to be 80 N 140W, per their web page ( http://www.catlinarcticsurvey.com/routemap ). If you use the grid line for 90W longitude (it runs through the Western headlands of Ellesmere Island), that start point would be ten grid lines (140-90=50/5=10) west. The listed line they are using on the Findings page is at 130W, not on the 140W line. They are in the middle of the first year ice in the their satellite image, not in the mixed ice.

  69. mark in austin
    Posted Apr 15, 2009 at 9:48 PM | Permalink

    today has the 2nd largest ice extent since 2003 which has around 70,000 km more. this is getting very interesting indeed. i know it is only one week, but man is it funny how this year is shaping up so far…

  70. vg
    Posted Apr 15, 2009 at 10:10 PM | Permalink

    In the context of millenia, this ice data means nothing pro AGW or anti-AGW. It’s strange that’s its even been discussed by serious scientist don’t you think? BTW same goes for sun.

    • Posted Apr 16, 2009 at 3:38 PM | Permalink

      Re: vg (#140),

      Totally agree. So if you can get all the AGW fanatics to stop using it as proof of anything, we’ll be in business.

    • Daryl M
      Posted Apr 20, 2009 at 9:17 PM | Permalink

      Re: vg (#140), If “this ice data means nothing” and “same goes for sun”, then what data is meaningful and what should “serious scientists” be discussing? Do enlighten us.

  71. BarryW
    Posted Apr 16, 2009 at 8:39 AM | Permalink

    JAXA shows 2009 extent today is above all but 2003 (27,000 km2 ) out of the last seven years.

  72. BarryW
    Posted Apr 17, 2009 at 8:10 AM | Permalink

    Ok, here is the JAXA for 4-17-2009. 2009 has just passed 2003 for largest extent for this date. The spread of values starts to compress about now so it will be interesting to see what happens next.

     
    year           extent       weekly change
    2003         13.63094            -0.39922
    2004         12.93062            -0.61563
    2005         13.12719            -0.21984
    2006         13.00281            -0.02219
    2007         12.97031            -0.24187
    2008         13.57734            -0.31781
    2009         13.64922            -0.09859

  73. Flanagan
    Posted Apr 17, 2009 at 9:56 AM | Permalink

    Well, looking at CT satellite pictures, it looks like we could expect a large melting rate in the following week. The ice in the Bering, Barents and Kara seas is falling into pieces.

    • BarryW
      Posted Apr 17, 2009 at 8:41 PM | Permalink

      Re: Flanagan (#144),

      Sort of a mixed bag. Barents CT area anomaly is below average, Kara is about on average, and Bering is well above. Okhotsk is well below also.

  74. AndyW
    Posted Apr 19, 2009 at 11:13 PM | Permalink

    Dr Walt Meiers has a nice overview of ice measuring technqiues over at WUWT and gives mild response on the current expedition up there to all the armchair critics, most of who will never have been further north than the artic circle :D

    Regards

    Andy

  75. Posted Apr 20, 2009 at 9:41 AM | Permalink

    From a comment on WUWT:
    David L. Hagen (07:46:23) : “Some links for those interested in exploring Ground Penetrating Radar in measuring snow/ice:…The GPR records have been used to validate accumulation records that reveal a doubling in snowfall in the southwestern Peninsula since 1850 allowing us to infer that this is a true climate signature and not a result of topography changes or flow…Note that this DOUBLING in snowfall is in the southwestern Peninsula which has the major temperature increase. i.e. the glacier is increasing in thickness, not melting.”

    More snow = more latent heat release = more atmospheric temperature = apparent heating trend in satellite record?

    See the Hagen comment at:

    http://wattsupwiththat.com/2009/04/19/nsidcs-dr-walt-meier-on-catlin-and-ice-survey-techniques/#comments

  76. Posted Apr 21, 2009 at 11:56 AM | Permalink

    Hey guys, I was wondering where I could find yearly NH sea ice anomaly data. Thanks.

    • DeWitt Payne
      Posted Apr 21, 2009 at 2:17 PM | Permalink

      Re: Carl (#150),

      Most sea ice data is absolute, not anomaly. Most of that is daily, not annual. Cryosphere Today has graphical daily area anomaly data for NH and SH sea ice. Individual daily data is also available on their iPhone page linked from the main page. Most of the digital resources are based on AMSR data that only goes back to 2002, JAXA and Uni-Hamburg e.g. See also the link in this comment above and others at that site that provide links to other sources like NSIDC.

  77. vg
    Posted Apr 21, 2009 at 3:20 PM | Permalink

    #149 Daryl: I will indeed.. read post carefully again “In the context of millenia”, BTW millenia = thousands of years (Latin). Unfortunately you wont live that long so you will never know LOL
    #150 Carl here (various charts etc..): http://wattsupwiththat.com/2009/04/21/leaving-the-ice-pack-behind/

  78. nevket240
    Posted Apr 21, 2009 at 3:30 PM | Permalink

    Growing Antarctic sea ice linked to damaged ozone
    Tue Apr 21, 2009 12:04pm EDT Email | Print | Share| Reprints | Single Page[-] Text [+]

    1 of 1Full SizeBy Alister Doyle, Environment Correspondent

    OSLO (Reuters) – An expansion of sea ice around Antarctica is linked to a hole in the ozone layer high in the atmosphere, according to a study on Tuesday that helps clear up a mystery about global warming.

    The findings, by scientists at the British Antarctic Survey (BAS) and the U.S. space agency NASA, explain an apparent contradiction between a thaw of ice in the Arctic to record lows and an increase in ice around Antarctica over the past 30 years.

    “This new research helps us solve some of the puzzle of why sea ice is shrinking in some areas and growing in others,” John Turner of BAS, the lead author of the report, said.

    The scientists said damage by manmade chemicals to the ozone layer, which shields the planet from ultra-violet rays that can cause skin cancer, cooled the stratosphere and disrupted wind patterns around Antarctica.

    The shift meant winds blew off the continent more often, cooling the sea and creating more ice, they said. Scientists found a hole in the ozone layer over Antarctica in the 1980s and traced it to chemicals once used in refrigerants or hairsprays.

    “While there is increasing evidence that the loss of sea ice in the Arctic has occurred due to human activity, in the Antarctic human influence through the ozone hole has had the reverse effect and resulted in more ice,” Turner said.

    Sea ice around Antarctica has expanded at a rate of around 100,000 sq kms (38,610 sq miles) a decade since the 1970s and covers an area of about 19 million sq kms at its winter maximum, doubling the size of the continent.

    ARCTIC

    By contrast, summer sea ice around the North Pole shrank in 2007 to the smallest since satellite records began in the 1970s. The U.N. Climate Panel says warming is caused by greenhouse gases from burning fossil fuels that will bring more floods, heatwaves, droughts and rising sea levels.

    “Although the ozone hole is in many ways holding back the effects of greenhouse gas increases on the Antarctic, this will not last, as we expect ozone levels to recover by the end of the 21st century,” Turner said in a statement.

    Tom Lachlan-Cope, a BAS meteorologist and one of the co-authors of the study in the journal Geophysical Research Letters, said Antarctica’s sea ice had expanded most in the Ross Sea, south of New Zealand.

    “It’s the classic way that sea ice is produced. You get an offshore wind which blows the ice away from the shore and exposes open sea water which then freezes over because of the cold air,” he told Reuters.

    Understanding Antarctica is a priority for scientists since it locks up enough ice to raise sea levels by 57 meters (190 ft) if it were ever to melt. Even a tiny thaw could threaten low-lying Pacific islands, or cities from New York to Beijing.

    (Editing by Farah Master)

    © Thomson Reuters 2009 All rights reserved

    you guys have got it all wrong. what you have to do is change your story everyday. That way you keep in front of things rather than checking from behind.
    regards

  79. BarryW
    Posted Apr 21, 2009 at 8:19 PM | Permalink

    Speaking of anomalies, the 2009 extent has been anomalous for awhile now. The extent loss has been relatively flat (the extent actually grew today). While the other years (using JAXA) have moved closer to the average, 2009 is increasing it’s separation.

    • DeWitt Payne
      Posted Apr 21, 2009 at 8:54 PM | Permalink

      Re: BarryW (#154),

      Actually it’s running parallel, more or less, to the 1979-2007 average rather than the 2002-2008 average. See the Arctic ROOS graph.

      • BarryW
        Posted Apr 22, 2009 at 7:32 AM | Permalink

        Re: DeWitt Payne (#155),

        Yeah, I saw that, though I keep expecting them to announce some sort of sensor problem. Also the area graph at ROOS ‘looks’ like the area is within 1 STD of the 1979-2007 mean. I wish some of these sites would provide the data that was drawn in their graphs so I could look at it a little closer.

        • DeWitt Payne
          Posted Apr 22, 2009 at 8:05 AM | Permalink

          Re: BarryW (#158),

          It probably is within 1 STD. When I regress the average NH sea ice area from Uni-Hamburg (2003-2007) against the 1979-2000 average from Cryosphere Today, the intercept is 1.11 Mm2. So if you don’t detrend the data, then the STD of the 1979-2007 data range that Arctic ROOS uses should be on the order of 0.5 Mm2. The CT anomaly has been as low as -0.299 recently and is currently -0.526 Mm2.

  80. vg
    Posted Apr 21, 2009 at 11:23 PM | Permalink

    #155 These people (NOREX) made major “downwards” changes to their graph last year when ice was about to bounce over the “normal line”. Sorry but don’t trust them (they gave no explanation: see WUWT “best Science Blog” last year). Expect to see same from them very soon. For a record of sea ice “adjustments” (note ALWAYS down, NEVER up)…see here:

    http://mikelm.blogspot.com/2007/09/left-image-was-downloaded-from.html

  81. AndyW35
    Posted Apr 22, 2009 at 1:24 AM | Permalink

    Sea ice adjustments do go up VG, so your assertion they are always down is quite frankly wrong. Lets stick to the facts in this thread and thoughts on the “why” to explain the facts and lets leave conspiracy theories to WUWT and Steve Goddard.

    Regards

    Andy

  82. vg
    Posted Apr 22, 2009 at 9:46 PM | Permalink

    #158 Andy show me just ONE ice extent “adjustment” that has gone up in the past 5 years. Note: cryosphere has removed its comparisons for NH ice current (2009) versus past. NH ice is now within normal limits SD according to DMI and AMSR (the only ones I trust are DMI, there Danish, LOL just a joke)

  83. AndyW
    Posted Apr 22, 2009 at 11:22 PM | Permalink

    #168. NDSIC adjusted upwards only 2 months ago…

    http://nsidc.org/arcticseaicenews/2009/021809.html

    http://nsidc.org/arcticseaicenews/2009/022609.html

    “Using F13 data instead of F15, the September daily minimum that we reported on September 16, 2008, changed from 4.52 million square kilometers (1.74 million square miles) to 4.54 million square kilometers (1.75 million square miles), within the margin of error for daily data.”

    You’re going to say now “apart from that one case ” I bet ! :-)

    The first (uncorrected) drop of 100k happened yesterday, rather unsurprisingly given the later start to the melt season. It does look now though it has started the “plunge” ..or maybe not…

    Regards

    Andy

  84. John Baltutis
    Posted Apr 23, 2009 at 12:34 AM | Permalink

    Roy Spencer says http://www.drroyspencer.com/2009/04/some-global-warming-qa-to-consider-in-light-of-the-epa-ruling/

    As can be seen in the graph below (updated here through April 21, 2009), 2007 was the year when summer ice melt resulted in a 30-year record low in sea ice coverage. In 2008, the ice recovered somewhat. And from looking at 2009, we might well see further recovery this summer. Based upon the PDO index (above) it could be we have entered a new cooling phase of the PDO, which might explain this sea ice recovery, as well as our recent return to colder, snowier winters in the Northern Hemisphere.

  85. vg
    Posted Apr 23, 2009 at 1:28 AM | Permalink

    Andy Point taken and conceded in this case. BTW I trust NSIDC data Walt posts frequently on WUWT

  86. Flanagan
    Posted Apr 23, 2009 at 2:41 AM | Permalink

    The JAXA data actually show a quite rapid decrease now, and we’re so to say back at the 2003 level. .

  87. AndyW
    Posted Apr 23, 2009 at 4:11 AM | Permalink

    No problem VG, these data sources can always have cockups or faulty equipment, I just think that if the claim is that the scientists are altering the data to show what they want to show then more evidence is needed than just spotting a change in graph data and jumping to conclusions.

    That certainly is a topic for WUWT but this thread tends just to look at the data with related musings.

    Regards

    Andy

  88. DeWitt Payne
    Posted Apr 23, 2009 at 9:39 AM | Permalink

    JAXA update:

    4/21/2009 13527656
    4/22/2009 13437969 -89687

    The recent drop in concentration makes it likely that on the order of 1 Mm2 of extent will be lost in the next two weeks. The rate anomalies for CT area and JAXA extent have diverged recently (see graph, EWMA smoothed rates, extent rate anomaly from JAXA 2003-2008 average, area rate anomaly from CT 1979-2000 average, UL and LL are +/- 95% calculated assuming iid and normality so should be taken with lots of salt).

    • AndyW35
      Posted Apr 23, 2009 at 2:30 PM | Permalink

      Re: DeWitt Payne (#165),

      I recall Chris saying somewhere that weather patterns will create a large melt in the Barings in that time period.

      Regards

      Andy

    • BarryW
      Posted Apr 24, 2009 at 11:08 AM | Permalink

      Re: DeWitt Payne (#165),

      Looking at the CT images it looks like the Barents sea is about ready to go. The concentration looks much worse than the random sample of images I looked at for the same time period.

    • BarryW
      Posted Apr 24, 2009 at 11:08 AM | Permalink

      Re: DeWitt Payne (#165),

      Looking at the CT images it looks like the Barents sea is about ready to go. The concentration looks much worse than the random sample of images I looked at for the same time period.

      • Posted Apr 24, 2009 at 12:51 PM | Permalink

        Re: BarryW (#172),

        The Barents is actually going through a rather substantial late-season expansion of sea-ice. Cold northwesterly winds have been blowing over the Barents for the last week almost continuously and pretty much for 80% of April. Hence, thicker first year and multi-year ice is being blown towards Novaya Zemlya and as it breaks up new ice forms in the leads but it not as readily surveyed by microwave sensors until it gets a couple inches thick.

        Go through the MODIS Arctic subset for the last couple weeks and you’ll see the near continuous flow of cold air over the open water creating the distinctive cloud streets. If you focus in on the 250m images you can see how new ice has been forming in strips ahead of the main pack ice and between leads within the pack ice as its blown apart.

        The concentration will rise once the winds turn from the south due to compaction and ongoing replenishment of ice from the trans-polar drift.

        • AndyW35
          Posted Apr 24, 2009 at 1:07 PM | Permalink

          Re: Tom Woods (#173),

          That’s not going to effect the extent graphs we are following though, it will the area graphs if true. So extent will still drop if your summary is correct.

          Regards

          Andy

  89. AndyW
    Posted Apr 23, 2009 at 10:57 PM | Permalink

    Preliminary figure another 100k melt, just.

    SST’s anomalies for Barings sea is still cold.

    http://weather.unisys.com/surface/sst_anom.html

    perhaps connected to the PDO??? So that may be a contributing factor to the late start for the main melt sequence.

    Regards

    Andy

    • Posted Apr 24, 2009 at 10:34 AM | Permalink

      Re: AndyW (#167),

      Where’s the Barings Sea? Did you mean Bering or Barents? Just curious.

      • AndyW35
        Posted Apr 24, 2009 at 1:03 PM | Permalink

        Re: Jeff Alberts (#170),

        Perhaps the Bearing sea? Where all the Polar bears have no ice :D I invariably spell Antartica and Artic as well as I always forget to put the c’s in !

        It was Bering in this case, sorry for the confusion.

        I’m not even going to attempt to spell the Russian seas …. if only this Apple computer did cut and paste, oh the nercy, I knew I should have bought one of those cheap Microsoft Windows machines !!!! Or should I????

        Regards

        Andy

        • BarryW
          Posted Apr 24, 2009 at 3:37 PM | Permalink

          Re: AndyW35 (#174),

          Doesn’t do cut and paste? What OS/Web Browser are you running?!

  90. vg
    Posted Apr 24, 2009 at 1:01 AM | Permalink

    #161 Andy: you were absolutely right in this case and it just goes to show that we (I) as a skeptic should not jump to conclusions. From being an absolute believer in AGW when I saw this graph about 3 years ago

    Then read Svenmarks paper on cosmic rays, and began to be a bit skeptical

    http://cei.org/gencon/019,05568.cfm

    and began to investigate further with WUWT and Climate audit and the fact that my dad was a meteorologist
    http://www.nature.com/nature/journal/v135/n3417/abs/135654a0.html and would be turning in his grave at the preposterous nonsense that is being fed to us day to day. In fact I don’t think any of the ice or temp data means anything in the context of “climate” that is millenia = thousands of years. I think current data proves me right. BTW I am convinced beyond any doubt from the dat I have seen (I am a scientist Phd etc) that there has been no significant change in any climate data over the past 100 years. Cheers

  91. BarryW
    Posted Apr 24, 2009 at 7:56 AM | Permalink

    Here is the JAXA extent for this week. 2003 and 2009 are very close, but the downturn seems to have started.

     
    year           extent       weekly change
    2003         13.32594            -0.20937
    2004         12.69109            -0.20859
    2005         13.04469            -0.06687
    2006         12.93656            -0.06125
    2007         12.80125            -0.15281
    2008         13.13547            -0.34422
    2009         13.33781            -0.26328

  92. vg
    Posted Apr 24, 2009 at 3:16 PM | Permalink

    #164 Andy in hinsight yes that was the ONLY case as I recollect where it was put “up” rather than “down”. I think that one was so blatant that they had to do something though as I said I trust NSIDC. There is a catalog of changes here

    http://mikelm.blogspot.com/2007/09/left-image-was-downloaded-from.html

    and more recent specific changes here

    http://wattsupwiththat.com/2008/12/13/something-is-rotten-in-norway-500000-sq-km-of-sea-ice-disappears-overnight/

    here

    as posted on WUWT: “I wouldn’t pin too much hope on the ICE_AREA chart. I remember last Dec. 9th when it indicated that the area was not only normal, back in the 1 standard deviation range, it had actually touched the “Average” (black) line. Two days later on Dec. 11 the last three months had been adjusted (“corrected”) such that it was not even the 1 standard deviation range. (I believe this was covered on WUWT) I wouldn’t be too surprised by another “correction”.

    It seems a consistent pattern, when the data doesn’t look “correct” (i.e. too cold, too much ice, etc.) AGWers search until some corrective factor is found and applied. But if the data agrees with expectation there is no need to seek corrective measures, the data is obviously correct.”

    and of course now we ain’t allowed to compare current ice here
    http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png with previous ie (1980) I can see why…

    • AndyW35
      Posted Apr 24, 2009 at 3:40 PM | Permalink

      Re: vg (#176),

      Hi VG,

      Did Mikel ask the University why it had changed and what was their response?

      Regards

      Andy

  93. Posted Apr 24, 2009 at 7:26 PM | Permalink

    vg:
    April 24th, 2009 at 3:16 pm
    #164 Andy in hinsight yes that was the ONLY case as I recollect where it was put “up” rather than “down”. I think that one was so blatant that they had to do something though as I said I trust NSIDC. There is a catalog of changes here

    http://mikelm.blogspot.com/2007/09/left-image-was-downloaded-from.html

    and more recent specific changes here

    http://wattsupwiththat.com/2008/12/13/something-is-rotten-in-norway-500000-sq-km-of-sea-ice-disappears-overnight/

    here
    as posted on WUWT: “I wouldn’t pin too much hope on the ICE_AREA chart. I remember last Dec. 9th when it indicated that the area was not only normal, back in the 1 standard deviation range, it had actually touched the “Average” (black) line. Two days later on Dec. 11 the last three months had been adjusted (“corrected”) such that it was not even the 1 standard deviation range. (I believe this was covered on WUWT) I wouldn’t be too surprised by another “correction”.

    But if you’d have looked carefully you’d have noticed that the upper curves were different from the lower ones with the Average curve whereas they should be identical. The upper curve stayed the same and the lower ones were corrected, both curves were identical once that was done. The reason for the change was explained at the time.

    • bender
      Posted Apr 25, 2009 at 6:43 AM | Permalink

      Re: Phil. (#180),
      I guess the suspicious “corrections” were just that: corrections. So much for the conspiracy theory.

  94. tty
    Posted Apr 25, 2009 at 1:23 PM | Permalink

    AndyW (175):

    If you are going to complain about russian names, you should pick russian names like Laptev.

    Bering was a Dane and Barents Dutch.

    • AndyW35
      Posted Apr 25, 2009 at 11:30 PM | Permalink

      Re: tty (#182),

      Your reading skills are worse than my spelling skills :p I was indicating with my poor spelling I wasn’t even going to attempt the Russian seas around the Arctic (poking fun at myself), as we had already been talking about the Barents and Bering I obviously wasn’t talking about them in this instance.

      Regards

      Andy

  95. Jim Arndt
    Posted Apr 25, 2009 at 5:04 PM | Permalink

    Phil #180

    Two days later on Dec. 11 the last three months had been adjusted (“corrected”) such that it was not even the 1 standard deviation range.

    I was my birthday and need some excitement. LOL

  96. Shawn Whelan
    Posted Apr 26, 2009 at 8:26 PM | Permalink

    Looks like the AGW proponents aren’t making any predictions this year, after last years way off the mark predictions.

  97. DaveM
    Posted Apr 27, 2009 at 7:16 AM | Permalink

    Boy! Am I glad I got here early!!! Look at all the good seats! I even brought extra popcorn and “drinks” etc. Wait a minute… I’m not that early. Should be good skiing on the graphs by now. More like a bunny trail. Oh well. At least I’ll be here when it starts though. Any day now?

    BTW What source are we using in place of CT? Will Dewitt be providing the colour commentary this year? Who is on graphs? How much for the leg warmers?

    Cheers all! Here’s to a good season’s ice melting fun! As others will once again take up the travails of “Baby Ice” this spring, I’m gonna be rootin’ for the terrible twosies, or “Toddler Ice”. Will it learn to walk, or just fall flat on it’s backside? Will the Toddler Ice use the Baby Ice as an “Ice Shield” to save itself? When will the beverage cart be coming around next? I already drained my first pint here…

    Oh the anticipation!

    • DeWitt Payne
      Posted Apr 27, 2009 at 12:51 PM | Permalink

      Re: DaveM (#186),

      It’s way too soon to start projecting a September minimum or average from the current data. They don’t even have that graph on the Uni-Hamburg page anymore. Late June or early July is more like it. Even then, the range calculated from data from previous years will be large. If the AMO index continues to drop, I would bet that the 2009 minimum will exceed 2008. At the moment, the Spring average (April, May, June) is running a little above 2008 but less than 2003. If that continues then 12.08 Mm2 would be about right for the average calculated from JAXA data.

  98. DaveM
    Posted Apr 27, 2009 at 7:21 AM | Permalink

    BTW I will be posting from now on as “INGSOC”. I have found it to be a more wearable moniker given the current “state” of affairs.

    Once again, Tally Ho! And bring on the singing Cats!

  99. AndyW
    Posted Apr 28, 2009 at 11:28 PM | Permalink

    I’ve noticed that ice extent around Novaya Zemlya is still increasing, this will be reducing the drop rate currently.

    Regards

    Andy

  100. INGSOC
    Posted Apr 29, 2009 at 8:52 AM | Permalink

    Rather interesting method here. (Link to translated radio story. May have to cut and paste)

    http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.radiobremen.de%2Fwissen%2Fnachrichten%2Fwissenawipolararktis100.html&sl=de&tl=en&history_state0=

    I haven’t seen such a device used for this purpose before… Perhaps this group is on to something?

  101. INGSOC
    Posted Apr 29, 2009 at 9:00 AM | Permalink

    More on post 190 at WUWT. My link provides scant details… My apologies. They towed what looks like a sonar “fish” behind a DC3 @ 200 feet over the ice cap.

  102. AndyW
    Posted Apr 30, 2009 at 11:26 PM | Permalink

    The JAXA graph is now well above 2003. Looking at the latest Bremen AMSRE the amount of ice in the European sector is still very large, also the ice in the Bering sea is sitting still in colder waters which seems to be helping it survive, though it is very fractured. The ice in the Barents will rapidly go because it is so young.

    Does anyone remember such a big Polynya around the top of Greenland last year? It’s the size of Wales ! :)

    Regards

    Andy

  103. Geckko
    Posted May 1, 2009 at 7:08 AM | Permalink

    I had a look at the NSIDC seasonal sea ice extent plot:

    and thought there was something curious about it. It occurred to me that if I was to model seasonal sea ice loss in the Arctic, one feature of the functional form I would use would be a partial differential equation that linked the rate of change of sea ice extent to the present level of sea ice extent (on the basis that if there is greater extent then the NH seasonal warmth would encroach more quickly at the margin – i.e. larger sea ice extent means more southerly sea ice).

    But for the last month and most notably now, the level of sea ice extent is very close to the 1979-2000 average, but the first derivative appears lower. But then this is slightly counter intuitive given that we are supposed to have a larger proportion of “baby ice” that should be more responsive to seasonal change.

    Of course the rate of sea ice loss will only accelerate from here through summer, but at present it looks curious.

    • Posted May 1, 2009 at 10:11 AM | Permalink

      Re: Geckko (#193),

      But for the last month and most notably now, the level of sea ice extent is very close to the 1979-2000 average, but the first derivative appears lower. But then this is slightly counter intuitive given that we are supposed to have a larger proportion of “baby ice” that should be more responsive to seasonal change.

      At this time of year almost all the ice at the perimeter is first year ice, in fact in the Bering Sea which melts rapidly at this time of year much of the ice is only a month or so old, this is the case every year. There is some multiyear ice at the perimeter in the vicinity of the Fram strait this varies significantly from year to year depending on the drift and this spring the outflow has been strong.
      For example:
      The impact on the composition of the ice inside the Arctic ocean itself won’t be felt until later in the year.

  104. Geckko
    Posted May 1, 2009 at 7:11 AM | Permalink

    Forgot to add the other piece of the conundrum, that is I would have though average temperatures are still above 1979-2000 averages for the Arctic region.

  105. Earle Williams
    Posted May 1, 2009 at 9:52 AM | Permalink

    INGSOC,

    That is an EM bird they towed. It uses electromagnetic coils to induce currents in the “ground” and measures the strength of the induced EM field. It’s a big fancy version of a metal detector. Same principle anyhow. These systems typically operate at several frequencies concurrently, thus providing a means to calculate the electrical conductivity of the “ground” at several depths. It is a bread and butter method of mineral exploration around the world.

  106. BarryW
    Posted May 1, 2009 at 11:47 AM | Permalink

    JAXA extent for this week. Now about a quarter of a million sq km above the others. The slope of the extent line looks much flatter than previous years.

     
    year           extent       weekly change
    2003         12.87406            -0.40297
    2004         12.52359            -0.16328
    2005         12.75500            -0.25609
    2006         12.44875            -0.45266
    2007         12.63375            -0.12266
    2008         12.91578            -0.18906
    2009         13.16203            -0.14906

  107. Mike Bryant
    Posted May 1, 2009 at 9:10 PM | Permalink

    Nice NH sea ice graph from Bill Illis:

  108. snowmaneasy
    Posted May 1, 2009 at 11:35 PM | Permalink

    I have been reading all of the above posts and was wondering why no one looks at the following….

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

    you will notice that the most recent plot puts the area at 13,105,625 km2 (May 1, 2009) and that this point is greater than all of the other areas for his time of the year

    • DeWitt Payne
      Posted May 2, 2009 at 9:09 AM | Permalink

      Re: snowmaneasy (#199),

      why no one looks at the following….

      Actually we do. That page is referred to as JAXA. See #197 above for example.

  109. AndyW
    Posted May 2, 2009 at 9:59 AM | Permalink

    In fact the JAXA graph is the one thing that ties us all together, so although it is not very important in the grand scheme of things because it has such a short span of years it is very important to this group of people as a starting point for us all to discuss Arctic fluctuations. We are actually living it so to speak as it gets older, so experience can be tied in with data. Not something you can say for the record from 1979.

    I think it is quite important that “live” human experience is tied in with data to give some sort of perspective. The downside is that we have been doing it for only a couple of years. I hope Steve is still kindly giving us the opportunity for this perspective till at least 2020, it will take that long to get a feel for how it is going. :D

    Regards

    Andy

  110. snowmaneasy
    Posted May 2, 2009 at 10:31 AM | Permalink

    Re:DeWitt Payne201
    reply and
    paste linkAndyW:
    Thanks for that…yes I can see your point…

  111. Aylamp
    Posted May 3, 2009 at 1:41 PM | Permalink

    The latest “wake-up call”. [My parenthesis].

    “The ACIA [Arctic Climate Impact Assessment] report indicated that we might experience events of en [sic] ice free polar basin in the summer time by year 2050. The observation of withdrawal of sea ice and the expected dynamics of future changes presented at the conference indicate that such events might occur already within a decade. Yearly variations in sea ice extent may be significant, but the downward trend is clear.”

    http://arctic-council.org/filearchive/summary.pdf

    • Gerald Machnee
      Posted May 4, 2009 at 4:09 PM | Permalink

      Re: Aylamp (#203),
      I have a problem with that whole committee and especially having Al Gore in the first line.

      • bender
        Posted May 5, 2009 at 11:35 AM | Permalink

        Re: Gerald Machnee (#205),

        I have a problem with that whole committee

        Sounds to me like an ad hom dismissal of the data, pointed to by Aylamp, which indeed indicates a downward trend.

        • Richard Sharpe
          Posted May 5, 2009 at 10:08 PM | Permalink

          Re: bender (#209),

          Sounds to me like an ad hom dismissal of the data, pointed to by Aylamp, which indeed indicates a downward trend.

          I tend to agree that the data indicates a downward trend.

          I also think that there is good evidence that there have been downward trends and upward trends in the past.

        • Gerald Machnee
          Posted May 6, 2009 at 7:27 AM | Permalink

          Re: bender (#209),
          Yes, if you only look at 1979 to the present, you can say there is a downward trend. However we have been through this before. Data is incomplete for the last couple of centuries, but it has cycled. but that was not my main point.
          My target was the ACIA. I will not go into detail here. Their report has been discussed elsewhere. It is somewhat biased and does not examine all the factors. Their analysis of the temperature increases in the Arctic gives figures that are too high. And Gore has not done the studies so to have him on line one is nothing more than politics.

  112. AndyW35
    Posted May 4, 2009 at 11:03 AM | Permalink

    Rather amazingly the latest AMSRE plot shows the ice at the greatest extent it has been between Novaya Zemlya and Svalbard.

    This time last month it was clear water to the top of Nov Zem. This indicates this very “baby” ice will slough off really quickly as we go into the melt season properly. In the Bering sea the cold waters have held back the onslaught but are being overcome. I expect in this month we will get some pretty big numbers indeed on daily reduction compared to 2008.

    Temps to the west of Greenland have now increased so I am interested how the huge polynya will change over time.

    Regards

    Andy

    • Posted May 4, 2009 at 8:52 PM | Permalink

      Re: AndyW35 (#204),

      Rather amazingly the latest AMSRE plot shows the ice at the greatest extent it has been between Novaya Zemlya and Svalbard.

      This time last month it was clear water to the top of Nov Zem.

      Not surprising as there’s been a strong drift through there recently.

      This indicates this very “baby” ice will slough off really quickly as we go into the melt season properly. In the Bering sea the cold waters have held back the onslaught but are being overcome. I expect in this month we will get some pretty big numbers indeed on daily reduction compared to 2008.

      I agree, the Bering ice was more extensive than last year but half of it was only a ~month old so it melted fairly quickly once it got going. The ice is thinning in the Beaufort, Chukchi etc., not surprising given the strong transpolar flow.

  113. AndyW
    Posted May 4, 2009 at 11:05 PM | Permalink

    I can see, after looking again at your previous diagram again, that’s a good point Phil; seemingly aided by cooler conditions in that region as posted in the recent update from NSIDC

    http://nsidc.org/arcticseaicenews/

    Regards

    Andy

  114. markinaustin
    Posted May 5, 2009 at 5:45 AM | Permalink

    yet we have more ice than we have in 7 years…..

    should be a very interesting summer indeed.

  115. BarryW
    Posted May 5, 2009 at 7:56 PM | Permalink

    On another ice subject, I noticed that the Nenana Ice Classic breakup has occurred on May 1 of this year.

  116. Shawn Whelan
    Posted May 6, 2009 at 12:25 PM | Permalink

    I wonder if bender is predicting a new low for the ice this year?

  117. Shawn Whelan
    Posted May 7, 2009 at 8:04 AM | Permalink

    I noticed Phil and bender are quite subdued this year.

    • Posted May 7, 2009 at 11:06 AM | Permalink

      Re: Shawn Whelan (#215),

      Really, no more so than normal, probably it appears so because there haven’t been many idiotic posts on here (unlike WUWT where Goddard excels in that regard). As I posted on here earlier I don’t anticipate much of interest to happen before July in line with previous seasons, so far that’s been the case. The strong outflow through the Fram this spring leads me to think that there will be some interesting developments later in the year.

      E.g. Re: Phil. (#196),

  118. Stephen Wilde
    Posted May 7, 2009 at 3:02 PM | Permalink

    Looking at the ice extent figures for early May in the Arctic I notice a steady year on year increase from 2006, to 2007 to 2008 and now 2009.

    It looks like the trend in ice reduction actually reached it’s maximum after the summer melt of 2005 and that the 2007 melt only exceeded it due to unusual synoptics.

    Sorry that I can’t recall the link.

  119. Chris
    Posted May 7, 2009 at 4:49 PM | Permalink

    #217 “the 2007 melt only exceeded it due to unusual synoptics”

    Make that 2008 too in part: there were unusually warm and persistent southerly winds over northern Siberia in August i.e. just the right place and time to cause maximum loss of ice cover in the run up to minimum, and take 2008 well below “the pack”.

    2005: http://tinyurl.com/cn4g9v
    2006: http://tinyurl.com/cbfnao
    2007: http://tinyurl.com/chjm8h
    2008: http://tinyurl.com/deym67

    (I said “in part” with 2008 because another key reason was significantly thinner ice pre-summer-2008 than pre-summer-2007)

  120. Chris
    Posted May 7, 2009 at 5:17 PM | Permalink

    #216 “…The strong outflow through the Fram this spring…”

    Do you have a comparison of this spring with previous springs?

    Also, do you have a comparison of heat inflow at depth? The following only goes up to 2008 unfortunately…

    http://arctic-roos.org/observations/satellite-data/sea-ice/temperature-salinity-and-volume-fluxes-in-the-fram-strait

    Stephen Wilde may be interested in the following evidence of how the 2007 melt may have involved more than just unusual synoptics:

    “During the last decade a significant warming was observed in the Atlantic Water inflowing through Fram Strait to the Arctic Ocean. The first warm episode spanned 1998 to 2000, manifesting the most strongly in the West Spitsbergen Current, the second warm period has continued since 2004 onward, with a peak in late 2006. Now we are observing a decline in the Atlantic Water temperature but it is still higher than the long-term average.”

    ” In winters 2005 and particularly 2007 the intensive inflow of warmer than average Atlantic Water resulted in the high heat flux into the Arctic Ocean.”

  121. Chris
    Posted May 7, 2009 at 6:01 PM | Permalink

    #213 “I wonder if bender is predicting a new low for the ice this year?”

    Does anyone dare predict a new high i.e. highest minimum in (JAXA) history, with 2009 being to 2008 what 1996 was to 1995 (see e.g. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg )
    Note that the AMO was negative in March 2009 for the first time in March since March 1996. (The figure for April isn’t out yet as I type)

    http://www.cdc.noaa.gov/data/correlation/amon.us.data

    I think it’s possible, but unlikely. A bit like the Met Office perhaps with its 20 per cent chance of a cooler than average summer in the UK?

    http://www.metoffice.gov.uk/corporate/pressoffice/summer2009/

    Viz. it won’t be mentioned and it probably won’t happen……….but you never know and you heard it mooted here first :)

    • AndyW
      Posted May 7, 2009 at 11:40 PM | Permalink

      Re: Chris (#220),

      “Does anyone dare predict a new high i.e. highest minimum in (JAXA) history, with 2009 being to 2008 what 1996 was to 1995 (see e.g. ”

      I’d have to be more than half way through a full bottle of scotch to be that brave Chris. Interesting point of view though, made me think. I’d feel pretty safe saying it will be nearer to 2007 than 2003. In fact to me there is an outside chance it will split 2007 and 2008, but more likely 2005 and 2008. As a fun guess I’d say 4.9-5.0×10^6

      I thouht the Met Office were touting a warmer summer (again!)?

      My main interest this year is the northern or NE passage, will we have a circumnavagation this year by sailors ? Surely some yachts person should try to do it, get their name in the history books etc.

      Regards

      Andy

      • Shawn Whelan
        Posted May 8, 2009 at 11:54 AM | Permalink

        Re: AndyW (#223),

        Amundsen went through the NE passage in the early 1900’s. Thousands of others have also. Nothing new there.

        • Posted May 8, 2009 at 1:38 PM | Permalink

          Re: Shawn Whelan (#227),

          Re: AndyW (#223),
          Amundsen went through the NE passage in the early 1900’s. Thousands of others have also. Nothing new there.

          As I recall last fall when Berrimilla went through she was the 77th vessel to traverse the passage, and the 114th time it has been done..

        • Shawn Whelan
          Posted May 9, 2009 at 6:07 PM | Permalink

          Re: Phil. (#228),
          The Berrimilla went through the southern route of the NW Passage not the NE Passage.

        • Posted May 10, 2009 at 6:06 AM | Permalink

          Re: Shawn Whelan (#232),

          Indeed, as did Amundsen.
          Re: Shawn Whelan (#227),
          It was your comment:

          Amundsen went through the NE passage in the early 1900’s. Thousands of others have also. Nothing new there.

          He, of course, started that journey in 1918 and finished it on foot two years later, his ship took rather longer being towed out of the ice by a coastguard vessel in 1921 I think.

        • AndyW35
          Posted May 8, 2009 at 11:45 PM | Permalink

          Re: Shawn Whelan (#227),

          “circumnavigation” rather than navigation … I should have put the “of the Arctic” in after it to make it clearer. ( I am assuming here of course the NW passage being open is a given of course)

          Regards

          Andy

        • Shawn Whelan
          Posted May 9, 2009 at 6:06 PM | Permalink

          Re: AndyW35 (#229),
          Amundsen circumnavigated the Arctic back in the early 1900’s however not in the same year.

          The southern route of the NW Passage is commonly open. The Northern Route never opened last year and is very unlikely to open this year.

  122. Chris
    Posted May 7, 2009 at 6:24 PM | Permalink

    http://pafc.arh.noaa.gov/marfcst.php?fcst=FZAK80PAFC

    “…MAY 2009 YEAR GROUP ANALYSIS AND EARLY SUMMER OUTLOOK…

    THE YEAR GROUP FOR MAY IS 1986 WITH 2006 THE SECOND CHOICE. 1986 AND
    2006 WERE LA NINA YEARS WARMING TOWARD EL NINO WHICH IS THE SAME
    OUTLOOK FOR 2009. 2009 IS SLIGHTLY COLDER THAN 1986 BUT THE STRENGTH
    OF THE LA NINA PATTERNS IS SIMILAR. WHAT THIS MEANS IS THE NORTH
    PACIFIC IS COLDER THAN NORMAL BUT WILL WARM TO NEAR NORMAL THIS YEAR
    AND MAY ENTER AN EL NINO BY FALL.”

    So 2009 is spanning the generations in its year group: an atavistic memory of a previous solar minimum perhaps? Seriously though it is interesting that the far north Pacific should outdo 1986 for cold. As for any possible El Nino, it will be interesting to see what happens if strongly negative PDO and solar min continue (unlike in 1987) but that’s OT here…..

    • Posted May 7, 2009 at 8:10 PM | Permalink

      Re: Chris (#221),

      Although as far as the Nth Pacific is concerned the PDO is negative now whereas it was positive in ’86 which should mean the Nth Pacific should be warmer this year.

      Re: Chris (#219),

      #216 “…The strong outflow through the Fram this spring…”
      Do you have a comparison of this spring with previous springs?

      You can check it out here.

  123. Stephen Wilde
    Posted May 8, 2009 at 6:08 AM | Permalink

    Thanks, Chris,

    It seems to me that early May each year is a good time to discern any underlying trend.

    There is generally little variation from year to year at that time so the signal is not hidden by the large swings that can occur from year to year in the maximum and minimum figures.

  124. BarryW
    Posted May 8, 2009 at 8:41 AM | Permalink

    Here is this week’s JAXA extent data. 2009 is running about 500k km2 above the mean.

     
    year           extent       weekly change
    2003         12.45719            -0.39391
    2004         12.06109            -0.43297
    2005         12.40516            -0.29125
    2006         11.94313            -0.39813
    2007         12.31828            -0.30953
    2008         12.68047            -0.19750
    2009         12.85375            -0.28141

  125. Gerald Machnee
    Posted May 8, 2009 at 11:01 AM | Permalink

    As a sideline to predicting the lowest extent of ice this summer, we can also predict whether the Canadian Geographic Northwest Passage cruise from Sept 1-16, 2009 will make it through the planned route. See it at:

    http://www.adventurecanada.com/rcgs

  126. tty
    Posted May 9, 2009 at 4:11 AM | Permalink

    A circumnavigation would very difficult, except with an icebreaker. Either passage (NE and NW) is at best only open a few weeks, and they tend to be the same weeks.
    You would have to wait until as late as possible to see which is probably going to open first, then try to get through that as early as possible, and then head for the other at high speed and hope to get through before it freezes. It might be feasible in a good ice-summer with a fast ship, but I think you would still have an excellent chance of getting stuck over the winter.

  127. AndyW35
    Posted May 9, 2009 at 10:58 PM | Permalink

    Hi Shawn,

    My definition of a circumnavigation is the classic one of one voyage in this case. Agree with tty it would be all a matter of timing, however with a fast multihull or Open 60 and if the ice melted enough in the Beaufort and Siberian seas you could cut the corner and so do get between them would take a week say. If they are both open this year it will be interesting to see number of days of overlap. I’m sure it was more than 1 week last year.

    Regards

    Andy

  128. tty
    Posted May 10, 2009 at 2:28 AM | Permalink

    Amundsen did not circumnavigate the Arctic, he went through the southern arm of the NW pasage.

  129. Shawn Whelan
    Posted May 10, 2009 at 10:20 AM | Permalink

    Not true at all. Amundsen went throught the NE Passage and the NW Passage and he did circumnavigate the Arctic.

    “After World War I, Amundsen planned to drift from the Bering Strait towards the North Pole in the Maud. Taking the Northeast Passage to the Bering Strait (1918-20), he became the second man (the first was Nils Nordenskjöld)to sail along the whole northern coast of Europe and Asia.”

    http://history.howstuffworks.com/polar-history/roald-amundsen.htm/printable

    Nils Nordenskjöld
    “1878-79: The Swedish explorer was the first to complete a voyage through the Northeast Passage along the northern coast of Europe and Asia. Travelling in the steamship Vega, he started in 1878 from Norway and, after spending one winter ice-bound in the Arctic, finally emerged into the Pacific Ocean.”

    http://www.athropolis.com/map6.htm

    How did they do that before a hundred plus years of global warming warmed the Arctic?

    • Posted May 10, 2009 at 10:54 PM | Permalink

      Re: Shawn Whelan (#236),

      How did they do that before a hundred plus years of global warming warmed the Arctic?

      By taking several summers for each crossing and when necessary hiking the rest of the way.

      • Shawn Whelan
        Posted May 11, 2009 at 5:29 AM | Permalink

        Re: Phil. (#237),
        The boats crassed the length of the passage.

        Now you’re just being childish Phil.

      • RomanM
        Posted May 11, 2009 at 6:02 AM | Permalink

        Re: Phil. (#237),

        I don’t think that these criticisms constitute a fair assessment of the situation.

        As Shawn points out, each portion of the route had to be navigable at some point in time for the ships to get through. The fact that they might have occasionally gotten stuck (even to the extent of overwintering in the ice) could very well have been due more to chance than to the non-existence of an open path. In the late 1800s and early 1900s, there were no satellites or airplanes to quickly identify an open channel as there would be today.

        • Posted May 11, 2009 at 8:18 AM | Permalink

          Re: RomanM (#239),

          I don’t think that these criticisms constitute a fair assessment of the situation.

          It’s not a criticism, Shaun asked a question and I answered it, it certainly is a fair assessment, the journeys were made piecemeal. Of course we don’t know whether with modern methods of reconnaissance a route though would have been possible, however to try to suggest as Shaun does that the fact of making the journey indicates that the polar seas were as accessible as they are in the last few years is stretching the point. I guess Shaun intended the question to be rhetorical and that no one would answer, but he shouldn’t throw a tantrum when someone does so. As to your point about the route being navigable you might want to read the attached about how the Maud made the last stage of the journey.

          http://query.nytimes.com/mem/archive-free/pdf?_r=1&res=9407E0DB1731EF33A25753C2A9619C946095D6CF

      • Shawn Whelan
        Posted May 11, 2009 at 9:35 AM | Permalink

        Re: Phil. (#237),
        By taking several summers for each crossing and when necessary hiking the rest of the way.

        There is no basis in fact to your statement that both men hiked the rest of the way. You must read the links before commenting.

        Both men sailed their boats the length of the NE Passage. Amundsen went from Norway to the Bering Straight before turning around and attempting to drift over the North Pole.

        “After World War I, Amundsen planned to drift from the Bering Strait towards the North Pole in the Maud. Taking the Northeast Passage to the Bering Strait (1918-20), he became the second man (the first was Nils Nordenskjöld) to sail along the whole northern coast of Europe and Asia. In 1922 as the Maud began its drift, Amundsen left the ship to make a flight across the North Pole. However, damage to the plane forced him to cancel the trip.”

        Nils Nordenskjöld
        “1878-79: The Swedish explorer was the first to complete a voyage through the Northeast Passage along the northern coast of Europe and Asia. Travelling in the steamship Vega, he started in 1878 from Norway and, after spending one winter ice-bound in the Arctic, finally emerged into the Pacific Ocean.”

  130. Gerald Machnee
    Posted May 11, 2009 at 8:31 AM | Permalink

    Hello, we have another group of Passage sailors. In today’s Winnipeg Free Press we have a headline:
    Arctic voyage to focus on climate change
    The article can be found at:

    http://www.winnipegfreepress.com/breakingnews/arctic-voyage-to-focus-on-climate-change-44702157.html

    A crew of four plan to sail from Victoria, British Columbia on June 6 and take 4 months to sail the route. They plan to interview people along the way and see how climate change is affecting them.

    • Shawn Whelan
      Posted May 11, 2009 at 9:43 AM | Permalink

      Re: Gerald Machnee (#241),
      Are these the same guys that tried to kayak to the North Pole last year?

      And then the there is the Larsen voyage in the St. Roch.
      86 days to travel from Halifax to Vancouver across the Northern Route of the NW Passage in an underpowered (300hp) little wooden boat. Something he could not have accomplished last year or likely this year. And so after 65 years of AGW there is more ice in 2009 than in 1944.

      http://www.ucalgary.ca/arcticexpedition/larsenexpeditions

      • Gerald Machnee
        Posted May 11, 2009 at 10:17 AM | Permalink

        Re: Shawn Whelan (#244),
        No, this is a newbie:

        Cameron Dueck, who grew up a stone’s throw from Lake Winnipeg, didn’t get his sea legs until he moved to Chicago at the age of 21. The Red River College Creative Communications grad took a job writing for the Chicago Board of Trade. He took up sailing on Lake Michigan and there was no turning back.

        He moved on to Singapore but the financial reporter quit in 2004 to “boat-hop” his way across the ocean and get his sea legs.

        He went to work in Hong Kong till the ocean beckoned once more, and Dueck got the idea to sail the Northwest Passage and to make a mission of it.

        He quit his job in Hong Kong and borrowed money for this. They plan to do updates on the following: http://www.openpassageexpedition.com

  131. markinaustin
    Posted May 11, 2009 at 9:28 AM | Permalink

    this is getting comical….it may turn out to be an impossible summer to accomplish such a task eh?

  132. Gerald Machnee
    Posted May 11, 2009 at 10:36 AM | Permalink

    The Canadian Geographic is planning the northern route between Banks and Victoria Islands and back to Cambridge Bay. You can win a free trip at: http://www.canadiangeographic.ca/contests/northwestpassage/default.asp

    • Shawn Whelan
      Posted May 11, 2009 at 11:16 AM | Permalink

      Re: Gerald Machnee (#246),
      Ice conditions permitting.

      The Arctic froze up very quickly in the 40’s.
      A repeat of that is likely since history tends to repeat and the climate goes in cycles..

      • Gerald Machnee
        Posted May 11, 2009 at 11:35 AM | Permalink

        Re: Shawn Whelan (#247),
        BBBut, I was planning to win!.
        We can speculate now, but I expect we will have more interesting discussions this fall than we had last year. Nature usually does what Nature wants.

      • Shawn Whelan
        Posted May 11, 2009 at 1:14 PM | Permalink

        Re: Shawn Whelan (#247),
        The route they are going to follow stayed froze up last year and likely will this year since it has multiyear ice this time around and the Earth is cooling.

  133. tty
    Posted May 11, 2009 at 11:48 AM | Permalink

    The first voyage through the Northeast passage in one summer was done by Shmidt and Wiese in 1932. 1932 was admittedly an exceptional year, Zubov sailed around Franz Josephs Land for the first time and Sibiryakov actually circumnavigated Severnaya Zemlya (something that was not possible either in 2007 or 2008).
    The first W-E passage in one summer was in 1934.

  134. Gerald Machnee
    Posted May 11, 2009 at 1:24 PM | Permalink

    The Canadian Geographic ship is reinforced for ice, but I think it means contact not ice-breaking.

  135. hswiseman
    Posted May 11, 2009 at 1:41 PM | Permalink

    Open Passage Expedition should be a hoot. They are planning to SAIL the NW Passage in a 40 Foot SAILBOAT! Plus/Minus Expedition Days til Heli rescue? I bid 12 Days.

    • Shawn Whelan
      Posted May 11, 2009 at 2:30 PM | Permalink

      Re: hswiseman (#252),
      Lots of sailboats have already gone through. I don’t see anything special about this boat going through. When they get stuck the Coast Guard icebreakers rescue them.

      • Posted May 11, 2009 at 9:30 PM | Permalink

        Re: Shawn Whelan (#253),

        Lots of sailboats have already gone through. I don’t see anything special about this boat going through. When they get stuck the Coast Guard icebreakers rescue them.

        A total of ~25, 7 last year I think, Berrimiila was one of the smallest at 33′.

  136. markinaustin
    Posted May 11, 2009 at 6:11 PM | Permalink

    so here is a question….why if you go to this site:

    http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+001

    and click on 2000, 2004, and 2008 you see a steady trend upwards in terms of heat even though overall we have experienced cooling during that time period. this is for the 3300 foot level.

    • Gary A.
      Posted May 11, 2009 at 9:34 PM | Permalink

      Re: markinaustin (#254),

      Dr. Spencer commented about this the other day at Watts Up With That.
      Link

      Roy Spencer (17:25:35) :

      All:

      If you are monitoring the daily data at our Discover web page, to get the best idea of how the monthly anomaly will end up you should monitor ONLY channel 5, and compare the current month with the same month from ONLY the previous year.

      The difference between the two months, one year apart, will then be only an approximation of the year-to-year difference in anomalies. This is because the Discover data are only from the AMSU on NOAA-15, while our official UAH product trends & interannual variability are from the AMSU on the Aqua satellite. Aqua is kept in a stable orbit, and so has no issues with orbital decay and diurnal drift corrections. That’s why we use only it, and no NOAA satellites (which all have drifting orbits), for trends.

      We then use NOAA-15 for the geographic patterns of the anomalies, and constrain the NOAA-15 anomalies in zonal bands to be equal to those from Aqua. I need to spend a week at some point making limb correction equations for the Aqua AMSU, too, so that we can use it to help out on getting the spatial patterns. If you check the daily imagery for channel 5 at the Discover web site, you will see they have great fidelity and few artifacts, so we trust the monthly regional patterns the come from NOAA-15. My only concern is that the diurnal drift in NOAA-15 is probably causing a spurious component of the land-sea temperature differences.

  137. markinaustin
    Posted May 11, 2009 at 11:07 PM | Permalink

    thanks gary…not sure i understand it but i will take away the important info about channel 5!

  138. AndyW
    Posted May 12, 2009 at 12:22 AM | Permalink

    Looking at the page Shawn quoted for Amundsen I don’t see any evidence at all for Amundsen circumnavigating the North Pole. If you say he was the first to do the NW passage and the first to do the NE passage then that is fine, but that is not a circumnavigation. That’s two trips in different directions.

    Regards

    Andy

    • Shawn Whelan
      Posted May 12, 2009 at 7:34 AM | Permalink

      Re: AndyW (#258),
      If you take two halves of a circle you have a full circle.

      Amundsen may not have circumavigated the Arctic in one trip but he did circumnavigate the Arctic in his two trips.

      It is an old wives tale that Amundsen was stuck in the ice at Gjoa Haven for a couple years. He stayed to complete his scientific work and study the life skills of the Inuit.

      Many others have gone through the NE Passage. The Soviets were more a problem than the ice.

      • Posted May 12, 2009 at 9:09 PM | Permalink

        Re: Shawn Whelan (#259),

        It is an old wives tale that Amundsen was stuck in the ice at Gjoa Haven for a couple years. He stayed to complete his scientific work and study the life skills of the Inuit.

        Making a virtue out of necessity, when he arrived at Gjoahavn the Gjoa had just been freed from running aground in a storm by throwing cargo overboard. Then discovering the good harbor he decided to choose it for winter quarters “It was evident that the autumn storms had set in in earnest, and I knew that the waters further west were very shallow.” Winter set in a couple of weeks later so it was a good choice. The eskimo they encountered there told them that the ice that summer had been very sparse and that it wouldn’t be the same the following summer. Indeed that summer the lead only extended a few miles further west and ice was right up to the land on the east. “We never moved from that spot till Sept. 16th, but remained there watching the ice…..Evidently summer was over” Hansen’s expedition to Simpson Strait found that “the channel was filled up with ice both on their way out and on their return”.
        Clearly their chance of leaving for the NW Passage was nonexistent that summer.
        In summary A. said: “The summer had been cold and inclement and there had been very little water for navigation. We could only hope for better luck next year.” That year everything was frozen over by September 21st.

        • Shawn Whelan
          Posted May 13, 2009 at 7:13 AM | Permalink

          Re: Phil. (#263),
          Amundsen was in the Arctic to study the magnetic North Pole and find it. That was what he did for 2 years while also learning the survival skills of the Inuit. There was oppurtunities to leave, and the crew wanted to leave but Amundsen chose to stay and complete his work. That is the historical fact.

          The Northern Route of the NW Passage was first crossed in the early 1850’s.

  139. AndyW35
    Posted May 12, 2009 at 8:10 AM | Permalink

    No, that is not a circumnavigation, that is two trips in opposite directions, ie 2 half-circumnavigations. A circumnavigation must be in one direction.

    Regards

    Andy

    • Shawn Whelan
      Posted May 12, 2009 at 8:38 AM | Permalink

      Re: AndyW35 (#260),
      A circumnavigation must be in one direction.

      What do you base that on?

  140. AndyW35
    Posted May 12, 2009 at 10:59 AM | Permalink

    Because it is based on one route, not two in different directions. No definitions of circumnavigation are based on adding 2 routes together.

    Regards

    Andy

    • Shawn Whelan
      Posted May 13, 2009 at 7:06 AM | Permalink

      Re: AndyW35 (#262),
      Well then let us just say that Amundsen crossed both the NE Passage and the NW Passage and circled the Arctic.

  141. AndyW
    Posted May 12, 2009 at 11:38 PM | Permalink

    110 000 loss provisional for the day on the JAXA spreadsheet. The graph is now trending back towards 2008 and rejoining thr pack.

    Regards

    Andy

    • DeWitt Payne
      Posted May 13, 2009 at 9:23 AM | Permalink

      Re: AndyW (#264),

      The smoothed extent rate has been tracking the 2008 rate very closely for the last few days, so it isn’t falling back all that fast. The smoothed rate anomaly is almost exactly on the 2003 to 2008 average today and the area anomaly compared to the 2003 to 2008 average is +462,000 km2. 2009 will probably fall below 2003 fairly soon, but 2008 has some big losses coming up next week, so 2009 could still stay in second place.

      Cryosphere Today hasn’t updated their data on their iPod/iPhone page since last Thursday.

      • Len van Burgel
        Posted May 13, 2009 at 10:38 AM | Permalink

        Re: DeWitt Payne (#267),

        DeWitt Payne, I posted on wattsupwiththat the reply I received from Jaxa re the uptick on June 1/2
        It had to do with a parameter switching due to surface ice melt.
        Masahiro HORI from Jaxa advised:

        We are planning to improve the processing to make the gap much smoother in the coming year

        It is not clear if he means this June allready. If the changed algorithm is allready in place and we don’t see an uptick on June 1 2009, then the gain which 2009 has over 2008 and 2003 will reduce considerably.

        What do you think?

      • AndyW35
        Posted May 13, 2009 at 1:12 PM | Permalink

        Re: DeWitt Payne (#267),

        Hi Dewitt,

        That’s interesting about the smoothed rates, I was simply eyeballing the Jaxa graph and it has closed since the start of May. I can see the upcoming large drop in 2008 you mention so it will be interesting to see if 2009 can follow suit.

        After looking at the Bremen AMSRE for the last few days there is definitely a large fragmentation going on at the moment

        Which may be more down to winds rather than temps. It is certainly looking more “Swiss Cheese” like than last year if memory serves me correctly with far larger polynya this year rather than last. Has the drift patterns changed from last year to produce this? I’m looking at NW Greenland for instance.

        Regards

        Andy

    • Len van Burgel
      Posted May 13, 2009 at 10:24 AM | Permalink

      Re: AndyW (#264),

      The 110,000 has been revised down to 83 594.
      There are always two values posted each day. For the last month or so the revised value is about 20,000sq km lower, so don’t jump to conclusions too quickly. Wait for the revised data.

      • AndyW35
        Posted May 13, 2009 at 1:01 PM | Permalink

        Re: Len van Burgel (#270),

        What conclusions am I jumping to? I’m just stating facts. I know how they update, that is why I said “provisional”.

        Has Steve Goddard brainwashed you enough to come over here and try and pick a fight? :D :P

        Regards

        Andy

  142. Shawn Whelan
    Posted May 13, 2009 at 9:48 AM | Permalink

    Well then let us just say that Amundsen crossed both the NE Passage and the NW Passage and circled the Arctic.

    And Amundsen circled the Arctic before a hundred years of AGW.

    How was that possible?

    • Posted May 13, 2009 at 11:08 AM | Permalink

      Re: Shawn Whelan (#268),

      Already answered. Re: Phil. (#240),

      • Shawn Whelan
        Posted May 13, 2009 at 12:11 PM | Permalink

        Re: Phil. (#272),
        You answered and you were wrong and still are.
        What is the point in being wrong twice?

        Why do the so called scientist choose to ignore the facts and put a political spin on the truth?

        I imagine whoever is the moderator will delete this since I am questioning the scientific dogma.

        It is curious how Phil is allowed to insult WUWT or anything he wants and my comments are cut for any tiny indescretion. What’s up with that?

  143. Shawn Whelan
    Posted May 13, 2009 at 10:14 AM | Permalink

    Abraham Lincoln

    “If you call a dogs leg a tail how many legs does a dog have?”

    “Four, calling a dogs tail a leg doesn’t make it so”

    You guys are anti Licoln?

    To be expected from todays so called science.

    Stalin would be proud.
    Now deleat this so nobody knows I wrote the truth.
    That appears to be what modern science is all about.

  144. DeWitt Payne
    Posted May 14, 2009 at 12:01 PM | Permalink

    William Chapman replied to my email about the recent lack of updates at Cryosphere Today. Apparently a server upgrade broke their graphing software. They expect to have it fixed within the week. Then I’ll have to interpolate all the missing data. Groan.

  145. AndyW35
    Posted May 14, 2009 at 1:12 PM | Permalink

    Those guys always lagged anyway to be honest.

    This is interesting, the northpole cam is down to 1 this year rather than 2

    http://www.arctic.noaa.gov/gallery_np.html

    Last year they had a normal camera and a fish eye one that looks at 360 degree of sky. Wonder why the reduced coverage this year .. budget cuts??? :D

    Now the NE coast of Greenland is looking very fragmented, far more than this time last year. Soon the JAXA graph for this year will be rejoining the main sequence, I think there will be some big drops in the days ahead. Ok, the cold SST’s between Alaska and Russia have slowed the drop in extent so far in that region but if that’s all that a cold PDO, El Nina and 21st Century Maunder Minimum can do so far then I am less than impressed up to now. I bet it is at least mid pack by 1st June.

    Regards

    Andy

  146. markinaustin
    Posted May 14, 2009 at 9:01 PM | Permalink

    andy, as i understand it, the Maunder Minimum that we MAY be experiencing would take several more years to really see results. the lack of heat coming from the sun would take a good amount of time to start registering….

  147. markinaustin
    Posted May 14, 2009 at 9:40 PM | Permalink

    http://news.bbc.co.uk/2/hi/science/nature/8048898.stm

    what do we make of this?

  148. Chris
    Posted May 15, 2009 at 8:09 AM | Permalink

    Arctic ice extent still ~200,000km2 ahead of a year ago even adjusted for leap year. That’s a lot of ice you’re wishing away in quite a short time AndyW35 ;) But of course you may be right, time will tell……….

  149. Chris
    Posted May 15, 2009 at 8:15 AM | Permalink

    For “ahead of” read “greater than”

  150. Chris
    Posted May 15, 2009 at 8:21 AM | Permalink

    That’s about one and a half times the area(/extent!) of England FYI :) [130,410km2]

  151. Chris
    Posted May 15, 2009 at 8:32 AM | Permalink

    And final comment, I believe we have a blocking high keeping things on the cold side over the next few days in the far NE Atlantic, while it’s finally turning colder again over at least part of the far N Pacific

    http://pafc.arh.noaa.gov/marfcst.php?fcst=FZAK80PAFC

    “…..FORECAST THROUGH MONDAY…WEST OF 178W…COLDER TEMPERATURES OVER THE
    WEEKEND WILL SLOW THE RETREAT OF ICE…..”

    So the JAXA red line may be able to continue blazing a trail above all others for just a wee while longer?

    • Posted May 15, 2009 at 8:37 AM | Permalink

      Re: Chris (#285),

      Maybe but you missed this:

      THE ICE EDGE WILL MOVE 30 TO 40
      NM TO THE NORTH MAINLY BY SATURDAY.

      FORECAST FOR WATERS EAST OF 178W…WARMING TEMPERATURES WILL DIMINISH
      ICE ALONG THE EDGE. THE LITTLE REMAINING ICE IN BRISTOL BAY WILL MELT
      THIS WEEK. ICE MAY ENTER THE BAY FROM THE RIVERS THROUGH BREAKUP. THE
      PATCH OF ICE TO THE EAST OF THE PRIBILOFS WILL NOT REACH THE ISLANDS
      AND WILL DIMINISH GREATLY BY MONDAY. THE MAIN PACK ICE WILL MOVE TO
      THE NORTH 25 TO 35 NM THROUGH MONDAY.

  152. Chris
    Posted May 15, 2009 at 8:41 AM | Permalink

    #284

    Indeed. *A full* 4 days behind last year. Which was in turn a full 6 days behind 2007.

  153. Chris
    Posted May 15, 2009 at 9:16 AM | Permalink

    #286 I didn’t miss it – it was similar to previous forecasts for east of 178W, whereas the change I was pointing out was to cooling temperatures for west of 178W. But yes actually it turns out much of the (remaining) ice is east of 178W in any event.
    I found a good animated synoptic forecast for the North Pacific – obviously helpful for visualising what the text forecast is saying:

    http://www.stormsurfing.com/cgi/display_alt.cgi?a=npac_slp

  154. AndyW35
    Posted May 15, 2009 at 10:53 AM | Permalink

    Chris, you know it’s traditional to quote in units of “size of Belgium” rather than England :) You may be right as well, I just think that ice in the Barents is going to go quicker than an MP fills out an expense form.Feel free to link to this when it stays till August just out of spite.

    Off topic, the Met office have been dreadful with their 3 days forecast for Kent, the mass downpour predicted would not have impressed Noah.

    Regards

    Andy

  155. Maikdev
    Posted May 15, 2009 at 10:54 AM | Permalink

    In this image from Ron Kwok…

    …the multiyear sea ice extent at 2008/01/01 and 2009/01/01 looks virtually the same.

    But, looking at the direct images from Quikscat:
    2008:

    2009:

    I see that, in my opinion, Kwok´s graphic underestimates the multiyear sea ice extent at present 2009.

  156. AndyW35
    Posted May 15, 2009 at 11:20 AM | Permalink

    Interesting post Maikdev.

    I did a quick cut and paste as well for today’s comparison to a year ago, it’s big so just the link to my area at my ISP

    Regards

    Andy

    • BarryW
      Posted May 15, 2009 at 7:55 PM | Permalink

      Re: AndyW35 (#291),

      It seems like the losses this year are more from the Atlantic side than last year, or am I missing something?

  157. AndyW35
    Posted May 15, 2009 at 11:21 AM | Permalink

    Er, I think I need to practice links … maybe the cocktail hour refreshments didn’t help.

    Regards

    WeblinkMan

  158. BarryW
    Posted May 15, 2009 at 12:13 PM | Permalink

    JAXA for the week. Still paralleling 2008 which is the next closest, but this week may see some changes. 2008 started dropping this week with 2003 gaining the high ground. Still keep expecting 2009 to take a big hit at some point.

     
    year           extent       weekly change
    2003         12.24672            -0.15562
    2004         11.82531            -0.19516
    2005         12.12937            -0.23062
    2006         11.78578            -0.13078
    2007         11.98547            -0.29922
    2008         12.28562            -0.34469
    2009         12.47312            -0.33188

    • Len van Burgel
      Posted May 15, 2009 at 7:31 PM | Permalink

      Re: BarryW (#293),
      BarryW
      Am I looking at this wrong or are you calculating a 6 day week?

      • BarryW
        Posted May 15, 2009 at 7:51 PM | Permalink

        Re: Len van Burgel (#294),

        Ouch, your right, thanks.

         
        year           extent       weekly change
        2003         12.24672            -0.21047
        2004         11.82531            -0.23578
        2005         12.12937            -0.27578
        2006         11.78578            -0.15734
        2007         11.98547            -0.33281
        2008         12.28562            -0.39484
        2009         12.47312            -0.38063

  159. AndyW35
    Posted May 16, 2009 at 12:46 AM | Permalink

    It’s more fractured, the Barents ice gained a late spurt due to flows and colder weather but it is very baby indeed! SST’s have been warm in the North Atlantic again as well.

    I’d forgotten how much water there was in the Chukchi and Beaufort seas last year.
    I’m going to try another link here.

    Years

    Regards
    Andy

  160. Sean
    Posted May 16, 2009 at 5:31 AM | Permalink

    We see maps of multiyear ice eg Maikdev: 290. I can see is that if open water freezes, for the following months you can say is baby ice. But this stuff moves, and gets compacted, thickens, thins, so in most locations will not be straightforward to say were and when the ice was formed. If detection is based on thickness, should we not say thick ice, and show the thickness in metres. It would be very interesting to plot the volume. But you can not get from baby ice/ multiyear ice to a volume.

    I understand that if you take core samples, you may get more of the history, but the maps above look like satellite maps.

  161. Mike Bryant
    Posted May 17, 2009 at 8:58 AM | Permalink

    Maikdev,
    Also in the Kwok representation, why the extra white around the multi-year ice? Why is this technique employed? Wouldn’t it be better to keep the backgrounds similar to aid comparison? Is the white at the bottom masking some of the multi-year ice?
    I don’t understand why these niggling type of inconsistencies must occur over and over.

  162. AndyW35
    Posted May 17, 2009 at 9:22 AM | Permalink

    For the second time I am trying to make a charity bet with Steve Goddard on WUWT on ice extent with the winnings going to charity. Last time he did not take me up on my offer, shame he would have lost but a charity would have gained, this time lets see what happens. I have bet come June 1st Arctic extent on the JAXA graph will be less than 2008.

    I’m quite happy to lose to be honest, if I am wrong I will give my money to the London Air Ambulance.

    Strangely, although Steve is very bullish on his postings he seems re markedly reticent to put his money where his mouth is.

    Regards

    Andy

    • BarryW
      Posted May 17, 2009 at 10:18 AM | Permalink

      Re: AndyW35 (#300),

      Could you tell us how much you were betting?

    • Len van Burgel
      Posted May 18, 2009 at 1:21 AM | Permalink

      Re: AndyW35 (#300),
      June 1 is a not a good date to choose. It is the date for the change in algorithm and the usual uptick. Since it is not entirely sure what efffect that will have this year why not choose May 31?

      • AndyW
        Posted May 18, 2009 at 11:21 PM | Permalink

        Re: Len van Burgel (#304),

        They will definitely be having an uptick this year as well. As the uptick change in algorithm is the same each year it should not adversly effect results.

        I have managed to lose where I posted the bet now, unless it has been deleted? The thread I thought it was in it is not, as far as I can see. Can anyone else find it?

        It was only going to be a small wager, £5 or £10, certainly not my house :D

        Regards

        Andy

        • Len van Burgel
          Posted May 19, 2009 at 2:37 AM | Permalink

          Re: AndyW (#307),
          I still think the uptick on June 1 is somewhat unpredicatble as it sometimes is over two days and varies from year to year. In addition JAXA in an email a month ago said “We are planning to improve the processing to make the gap much smoother in the coming year.” We can’t be sure if that may allready be this June.

  163. Shawn Whelan
    Posted May 17, 2009 at 10:11 AM | Permalink

    You should bet him that that the ice will be lower than 2007.

  164. thefordprefect
    Posted May 17, 2009 at 6:49 PM | Permalink

    The “Russians” view of sea ice:

    http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2009

    mike

  165. INGSOC
    Posted May 18, 2009 at 7:36 AM | Permalink

    I haven’t seen much mention of this study by the Wegener Institute, so I thought I would provide the link and see what the resident experts here have to say.

    http://www.awi.de/en/news/press_releases/detail/item/ende_pam_arcmip/?cHash=ff957775e4

    I, of course, being relatively ignorant, have no valid opinion… I will however keep this report in mind during the “run to the bottom” of the ice extent this summer. For what it is worth, I have put my money on the “Toddler Ice” this race season. They don’t call ‘em “Terrible Twos” for nothing!

    P.S. It has only 3 been weeks or so, since I plunked down my lawn chair (on the front row no less!) for the show this year, and I’ve already run out of tequila! Methinks I’ll need to diversify… Mint Juleps? Banana Daiquiris?

  166. Shawn Whelan
    Posted May 18, 2009 at 11:49 AM | Permalink

    Alfred Wegener was the father of plate tectonics.
    His peers reviewed his work and the consensus of scientists declared he was wrong.
    Many decades later with the new evidence piling up the consensus of scence reversed their position and declared that he was correct.

  167. AndyW35
    Posted May 19, 2009 at 8:11 AM | Permalink

    Good point Len about the smoothi9ng, I had forgotten that. It can be the last day before the change then. As I can’t find my post it may be a mute point though.

    I make it that 2009 has about 180k+ to make up and 2008 had a couple of big days ahead of it, so it is a tough challenge. However I am still confident that the Atlantic side will come to my rescue….

    How do other people think 2009 will fair in the next 2 weeks or so?

    Regards

    Andy

  168. Shawn Whelan
    Posted May 19, 2009 at 11:58 AM | Permalink

    Snowing all over western Canada.
    That must slow down the melt.

    Heavy snowfall warning for Edmonton
    By Jamie Hall, Edmonton JournalMay 19, 2009 11:44 AM

    http://www.windsorstar.com/Technology/Heavy+snowfall+warning+Edmonton/1609032/story.html

  169. markinaustin
    Posted May 19, 2009 at 10:10 PM | Permalink

    andy made the call….;unless there is a large correction upwards in the morning, the melt off today was dramatic!

  170. DeWitt Payne
    Posted May 19, 2009 at 11:23 PM | Permalink

    Cryosphere Today graphs have finally been updated. Nothing dramatic. Ice concentration (CT area/JAXA extent) is dropping, but that’s normal for recent years. Even with the today’s (preliminary) large drop, JAXA extent remains above the previous six years, though not by much.

  171. AndyW
    Posted May 19, 2009 at 11:53 PM | Permalink

    2008 had a very big day today, 127K, however 2009 has had 300k in 3 days v 250k in 3 days last year, so 50k has gone. 2008 had a run of lower values from 21st and so I am hoping my Barents sea ice will not let me down. I’ve already sent a letter to Putin demanding they scrap som more nuclear subs in the region just to help out with the SST’s….

    Regards

    Andy

    • Len van Burgel
      Posted May 20, 2009 at 9:41 PM | Permalink

      Re: AndyW (#313),
      Andy
      Are you using Julian days (one day earlier in 2008) or the actual dates for comparison?
      If the provisional data released for today is adjusted down, the gap 2009 to 2008 will have blown out to 200K again (300K on a calendar date basis). However, the way the melt rate changes day to day and week to week, your proposed bet is still line ball.

      • AndyW35
        Posted May 21, 2009 at 1:30 PM | Permalink

        Re: Len van Burgel (#316),

        Hi Len,

        No I am not using Julian days, I am using Column B days which is purely a late 20thC way of measuring days based on the Microsoft Calendar …. :)

        Yep, it’s going to be very tight indeed I admit, it will not be the first time I have been horribly wrong, however I am still confident and it makes it more fun than waiting for the proper day to get ready to be excited, or not,in July …. it just passes time.

        Regards

        Andy

  172. AndyW
    Posted May 19, 2009 at 11:56 PM | Permalink

    These may be of interest

    Min
    Max

    Regards

    Andy

  173. AndyW
    Posted May 20, 2009 at 1:07 AM | Permalink

    Note, I used same days, the max or min for that year may have been a different day but I wasn’t concerned too much about absolute values, just the geographic distribution.

    Regards

    Andy

  174. Michael Hauber
    Posted May 20, 2009 at 11:39 PM | Permalink

    I just started looking at Canadian Weather office analysis charts a week or two ago (http://www.weatheroffice.gc.ca/analysis/index_e.html).

    Currently there appears to be a rather large high in the pacific and a significant low pressure complex over NE Russia. My guess is that this would be directing winds on an almost direct path from the tropical/subtropical pacific ocean to the Bering Straight end of the Arctic. However my weather watching experience is with sub-tropical Australian weather so I’m not sure if I’m assessing likely windstreams reasonably (if the winds cross isobars slowly, they may circle the high and end in SE pacific, if they cross isobars quick they’d get eaten by the NE Russian low). And I have no idea whether this set up is in anyway unusual, or happens all the time…

    • INGSOC
      Posted May 21, 2009 at 9:04 PM | Permalink

      Re: Michael Hauber (#317), http://pafc.arh.noaa.gov/pubfcst.php?fcst=FXAK68PAFC

      That cold air mass over the Canadian Arctic has been an almost permanent feature for the past 6 months. The forecast has the high ridge holding. I would not be surprised to see the two highs currently bracketing Alaska join up and form a formidable ridge stretching all the way South to the Baja! Here in Southwestern BC, we have not had the usual barrage of wet tropical air for weeks on end as has been common in the past few years. Much dryer and cooler. Nice in fact! (Just not if you are trying to start Tomatoes)

  175. snowmaneasy
    Posted May 21, 2009 at 11:32 PM | Permalink

    Just noticed a distinct up-tick in JAXA graph for 21st May…this once again takes ice coverage above all previous years. Anyone care to comment

    • DeWitt Payne
      Posted May 22, 2009 at 8:38 AM | Permalink

      Re: snowmaneasy (#320),

      The final JAXA ice extent normally posted the next day at 10 AM Eastern time never went below 2003 or 2008 for the same day of the year in the last few days. It was quite close to 2003, but still a little higher. The current large drop followed by slower than average loss (the day to day difference on May 20 was -1094 km2, small but still negative) is similar to what happened in 2008 but about 2 days early.

      Apparently the recent update at Cryosphere Today was a one time thing and their regular plotting software is still broken.

  176. snowmaneasy
    Posted May 21, 2009 at 11:38 PM | Permalink

    Can someone explain the JAXA anomaly “kink” on or around the 1st of June for virtually every year except 2004 ??

    • Posted May 22, 2009 at 1:06 AM | Permalink

      Re: snowmaneasy (#321),

      Warming temperatures/24hr sunlight begin to create melt ponds on the surface of the ice that the current processing algorithm ‘sees’ as open water. In recent years June 1st was around the date when JAXA switches to a different algorithm which counts those suspected melt ponds as ice covered, hence the uptick.

  177. DeWitt Payne
    Posted May 22, 2009 at 8:45 AM | Permalink

    The year to date average extent finally exceeded 2008 today by 65.5 km2. It’s still ~300,000 km2 behind 2003, but it’s ahead of 2004-2008.

  178. Bill Illis
    Posted May 22, 2009 at 9:19 AM | Permalink

    I’ve been tracking the Jaxa daily numbers compared to the Nasateam Algorithm from 1979-on. Jaxa used Nasa to help develop the algorithm it uses so they are reasonably consistent to each other (I’ve adjusted the Nasateam numbers down 400,000 to match them up) and this would not be consistent with the Bootstrap algorithm that the NSIDC uses.

    So here is how 2009 to date stacks up compared to all the other years from 1979 and with the two highest sea ice extent minimum years (1980 and 1996) and the two lowest minimum extent years (2007 and 2008).

    • AndyW35
      Posted May 22, 2009 at 12:46 PM | Permalink

      Re: Bill Illis (#325),

      What caused the divergence in 1996 from the normal downward gradient around this time?

      Regards

      Andy

      • Bill Illis
        Posted May 22, 2009 at 1:15 PM | Permalink

        Re: AndyW35 (#327),

        Nothing particularly special happened weather-wise in 1996. Global temps declined a little, the AMO declined a little, there was a minor La Nina but nothing to account for the trend.

        There may have been less ocean current/outflow along Greenland or Ocean temps might have been very cold along the ice pack margin at the time (according to the July 30th, 1996 archive pic although there may be a processing problem with this pic.)

        • AndyW35
          Posted May 22, 2009 at 10:39 PM | Permalink

          Re: Bill Illis (#328),

          Hi Bill,

          Thanks for that info. Given your graph which makes it easy to spot you can actually see it as well on the good old CT graph as well

          As summer jumps compared to the low winter and spring, however you really have to be looking for it a lot harder!

          Regrds

          Andy

  179. BarryW
    Posted May 22, 2009 at 9:40 AM | Permalink

    JAXA Extent for the week

     
    year           extent       weekly change
    2003         11.95875            -0.28797
    2004         11.49812            -0.32719
    2005         11.93297            -0.19641
    2006         11.49641            -0.28937
    2007         11.75531            -0.23016
    2008         11.77750            -0.50812
    2009         12.05422            -0.41891

  180. BarryW
    Posted May 22, 2009 at 8:50 PM | Permalink

    It looks like the JAXA extent change should become smaller and possibly go positive over the next ten days until the new algorithm kicks in.

  181. BarryW
    Posted May 24, 2009 at 10:57 AM | Permalink

    While it’s only one day I thought this was significant. JAXA extent for 2003 is now larger than 2009 for the first time in about a month.

    year       extent        change from yesterday
    2003   11.92531   -0.007968
    2004   11.40391   -0.035313
    2005   11.79016   -0.075000
    2006   11.37125   -0.054531
    2007   11.64188   -0.067188
    2008   11.72828   -0.020000
    2009   11.90891   -0.068594

  182. Flanagan
    Posted May 24, 2009 at 12:25 PM | Permalink

    And what do you think of the state of the ice in the Greenland sea? It’s really fractured to a point I haven’t seen before and it looks like it might be completely gone by the summer…

    • Posted May 24, 2009 at 1:42 PM | Permalink

      Re: Flanagan (#332),

      The satellite images confirm the impression from the microwave analysis.
      With the extensive North Water polynya to the west it might be possible to circum-navigate Greenland later this year!

      • AndyW35
        Posted May 25, 2009 at 12:38 AM | Permalink

        Re: Phil. (#333),

        Perhaps the chap in the canoe could give it a bash. Assuming Admundsen hasn’t already done that too!

        My bet on 2009 beating 2008 by June is reliant on the Atlantic side because last year 2008 had, by this time, lots of sea visible to the north of Alaska and stretching over to Canada which obviously hasn’t occurred this year. As Flanagan points out though to the East of Greenland and in the Barents it is very fragmented. With another greater loss today with the provisional results just out 2009 has halved the gap from 300 000 to 150 000 or so in 4 days. 2008 had a really bad day on the 29th so I won’t really know until the 30th whether it will time to uncork the champers.

        Regards

        Andy

  183. Maikdev
    Posted May 25, 2009 at 4:05 PM | Permalink

    Re: 321

    Answer from Japan:
    “It is not actual but an apparent increase which results from
    a switching of some parameters used in the sea-ice processing
    to those for summer processing on June 1.

    The switching of parameters is needed because the surface of
    the Arctic sea-ice becomes wet in summer due to the melting
    of ice which changes satellite-observed signatures of sea-ice
    drastically. The parameter switching is ususally done on June 1
    and October 15 every year.”

  184. Chris
    Posted May 25, 2009 at 4:55 PM | Permalink

    Looks like Greenland will float away within weeks. Look how far East Arctic ice coverage has been falling below even the long-term trend…..

    http://tinyurl.com/pxdoas

    As for the West Arctic, more dangerous curves…..

    http://tinyurl.com/ofzn6e

    Meanwhile check out a genuinely scary couple of graphs before they are corrected: Arctic Roos extent and area showing the 2009 red lines coming to a grisly end LOL

    http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic

  185. Chris
    Posted May 25, 2009 at 5:19 PM | Permalink

    #334 “My bet on 2009 beating 2008 by June is reliant on the Atlantic side”

    I should warn you that there are forecast to be some chilly temperatures on the Atlantic side for the rest of May – for example Spitzbergen with temperatures mostly well below freezing unlike the same time last year:

    http://www.weatheronline.co.uk/Norway/Spitzbergen.htm

    While on the Pacific side a “colder northerly flow” is forecast:

    http://pafc.arh.noaa.gov/marfcst.php?fcst=FZAK80PAFC

    • AndyW35
      Posted May 26, 2009 at 1:08 AM | Permalink

      Re: Chris (#337),

      I debated whether I should post some bravado here Chris but then decided against it :) Another 100k provisional result today so the gap is around the 100k mark now. Remaining days for 2008 were

      26 2008 11586250 -39688
      27 2008 11534531 -51719
      28 2008 11497031 -37500
      29 2008 11490156 -6875
      30 2008 11448750 -41406
      31 2008 11403906 -44844

      so 2009 needs to make water while the sun shines on the 29th. If we have that sort of amount in 2009 my heart will sink!

      Regards

      Andy

  186. Posted May 26, 2009 at 7:45 PM | Permalink

    FYI,NSIDC has stopped imaging sea-ice. http://nsidc.org/arcticseaicenews/index.html

  187. DeWitt Payne
    Posted May 27, 2009 at 8:45 AM | Permalink

    Arctic ROOS has pulled most of their data for May from their graphs. Comparing the SSM/I data from the F13 satellite to JAXA showed that the noise level in the F13 data increased significantly in mid-2008, so without heavy filtering, the SSM/I data from April 2008 on is at least somewhat suspect.

    Cryosphere Today still hasn’t updated, which makes me think they have more than a graphing software problem.

  188. Gerald Machnee
    Posted May 27, 2009 at 11:01 AM | Permalink

    Maybe it is time to resurrect the old bombers with the cameras again.

  189. nevket240
    Posted May 28, 2009 at 3:56 AM | Permalink

    http://www.reuters.com/article/scienceNews/idUSTRE54Q4SY20090527

    have a quick read of this rubbish. as I understand it the last paragraph is patently dishonest.
    regards

    • DeWitt Payne
      Posted May 28, 2009 at 3:26 PM | Permalink

      Re: nevket240 (#342),

      It’s contradictory. If the MOC slows down, the Arctic will cool so melting cannot continue to increase exponentially. It looks almost like a negative feedback. Not to mention that the MOC actually bears little relationship to a monolithic conveyor belt according to recent published research which I’m too lazy to look up. I vaguely remember Wunsch also saying something similar not too long ago. Seven percent/year for 50 years is about a 30 fold increase in rate. According to the UAH NoPol anomaly, the Arctic is already cooling as the AMO goes negative. See graph.

  190. Chris
    Posted May 29, 2009 at 8:20 AM | Permalink

    “Chris, you know it’s traditional to quote in units of “size of Belgium” rather than England” [AndyW35 #289]

    Now only 1.7 x size of Belgium greater ice extent than a year ago ;)

    5 27 2008 11534531
    5 28 2009 11586719
    Area of Belgium 30,528km2

    Good call in terms of recent narrowing of the gap, but still a lot of ice to melt for your bet to be correct re: June 1st?

  191. AndyW35
    Posted May 30, 2009 at 1:32 AM | Permalink

    Hi Chris,

    Yes it is looking very shaky I have to admit, probably out by somewhere between the metric units of Luxembourg and Belgium!

    Today needed to be a big day to capitalise on last years and it was moderate. Still two more days to go though.

    Regards

    Andy

  192. BarryW
    Posted May 30, 2009 at 2:57 PM | Permalink

    Was not able to post yesterday so these numbers are for today and the change over the last seven days (Sat to Sat)

    JAXA Extent

     
    year           extent       weekly change
    2003         11.64625            -0.28703
    2004         11.36250            -0.07672
    2005         11.38937            -0.47578
    2006         11.10453            -0.32125
    2007         11.36875            -0.34031
    2008         11.49703            -0.25125
    2009         11.55266            -0.42484

  193. Mike
    Posted May 30, 2009 at 10:35 PM | Permalink

    We’ll have to wait 12 more hours or so for the final results, but it looks like 2009 has caught up to 2008:

    May 29 2008 11490156*
    May 30 2008 11448750

    May 30 2009 11460313

    *If last year was like this year (no February 29th), the May 30th ice extent would have been 11490156.

  194. AndyW35
    Posted May 31, 2009 at 1:02 AM | Permalink

    Hi Mike,

    We’ll have to wait a bit longer than that as they won’t post May31 results until the corrected results well into June 1st.

    The provisional results today are very good so far,

    29 2009 11552656 -34063 -62500
    30 2009 11460313 -92343 -11563

    90k loss, no doubt they will put it down, but not too far I hope… but only 11k behind at the moment. It was 318k behind 10 days ago !

    Regards

    Andy

  195. AndyW35
    Posted May 31, 2009 at 5:48 AM | Permalink

    Sunny today at the north pole ( or wherever it has drifted to by now)

    No melt pools yet of course.

    Regards

    Andy

  196. BarryW
    Posted May 31, 2009 at 9:39 AM | Permalink

    Hmmm, I think we may have a winner unless there is a surge at the wire:

    JAXA extent as of 5/31 11:30 EST

    2008    11.49016
    2009    11.47813

  197. markinaustin
    Posted May 31, 2009 at 9:16 PM | Permalink

    seems like it goes back up over night every day…so i suspect it will get adjusted upwards tomorrow morning and 2009 will win by a wee bit. but it is a close call.

  198. Mike
    Posted May 31, 2009 at 11:44 PM | Permalink

    The preliminary result is in, and 2009 is in the lead by a very thin margin –

    May 31 2008 11403906
    May 31 2009 11393281

    It’s too close to call, so we’ll have to wait another day or two.

    On another note, any melting over the next week will be limited to the Russian side. Northern Alaska, Canada and Greenland are all forecast to have average or slightly below average temps, but Siberia is having a heat wave. Some parts of Siberia are 70 degrees F (21 degrees C) today, but the forecast for Wednesday through Friday is temps in the upper 80s and even lower 90s (30 degrees C)!

    http://www.wunderground.com/global/stations/24959.html

    Not good for any baby ice in the region.

  199. AndyW35
    Posted Jun 1, 2009 at 2:58 PM | Permalink

    Just squeaked in there .. phew. Doesn’t really say much for the summer minimum but at least it gave me some days of amusement in this slack time before the show starts.

    The main difference geographically wise between this and last year is that there is less open water on the Canadian side and more open water on the Russian side. Not by a huge margin but noticeable.

    Can someone tell me whether the PDO is making Northern Canada colder currently or in the recent past? Isn’t it supposed to make the USA and Canada cold and wet?

    Regards

    Andy

  200. Chris
    Posted Jun 2, 2009 at 8:27 AM | Permalink

    AndyW35:
    “I bet it is at least mid pack by 1st June.” (#277)
    “I have bet come June 1st Arctic extent on the JAXA graph will be less than 2008.” (#300)

    Well not quite mid pack, but I’d say you won your main bet (just). Although the waters are a bit muddied by the 1st June satellite adjustment, which means that 1st June 2009 has a higher extent value than 31st May 2008 (i.e. equivalent Julian day). So an unsporting observer could query your victory ;)

    5 30 2008 11448750
    5 31 2008 11403906
    6 1 2008 11459219
    6 2 2008 11507656
    6 3 2008 11452969

    5 31 2009 11402188
    6 1 2009 11446094

  201. Chris
    Posted Jun 2, 2009 at 2:32 PM | Permalink

    Northern Hemisphere snow area results are in for May 2009.
    A continuation of the weak recovery from the 2007 near-record May minimum:
    May 2009 18.364 Mkm2 (-1.885) 7th lowest snow area (in last 43 yrs)
    May 2008 17.681 Mkm2 (-2.568) 5th lowest
    May 2007 17.419 Mkm2 (-2.830) 2nd lowest
    Here’s a link to the site http://climate.rutgers.edu/snowcover (although it appears to have crashed just now as I was halfway through this post)

  202. Chris
    Posted Jun 2, 2009 at 2:45 PM | Permalink

    “Can someone tell me whether the PDO is making Northern Canada colder currently or in the recent past? Isn’t it supposed to make the USA and Canada cold and wet?” (AndyW35 #353)

    It does seem plausible that the cold SST anomalies in the NE Pacific (as represented by the -ve PDO) have been a major factor in Northern Canada’s recent cold. It’s been the place in the Northern Hemisphere with the largest negative temperature anomalies in the past 6 months:

    http://www.cdc.noaa.gov/map/images/rnl/sfctmpmer_180b.rnl.html

    (note this does not include the far northeast of Canada – here it has been much less cold than normal)

  203. AndyW35
    Posted Jun 2, 2009 at 3:51 PM | Permalink

    Thanks Chris for the info about Canada, definitely less clear sea up there at this time than last, in the Beaufort…

    Regards

    Andy

  204. Michael Jennings
    Posted Jun 3, 2009 at 9:43 AM | Permalink

    What is going on with JAXA? How do you go from an extent of 11446094 on 6/1 to 11,523,125 on June 2nd? This time of year that seems odd to say the least and I have to assume that one of these readings is terribly wrong. Chris may end up winning his bet after all if the June 1st reading is the wrong one.

    • Posted Jun 3, 2009 at 10:00 AM | Permalink

      Re: Michael Jennings (#358),
      Nothing is ‘going wrong with JAXA’, around this time of year a change in the nature of the ice surface begins due to surface melting which causes a change in the reflection of the microwaves. To account for this parameters used in the processing of the data are changed on June 1st and October 15th. This switch can result in the ‘blip’ you see and has done so most years in the JAXA record.

  205. Chris
    Posted Jun 3, 2009 at 10:18 AM | Permalink

    #358 I didn’t take part in the bet LOL I just thought it was interesting. Plus AndyW won his bet and credit to him. He proposed it (as I recall) as a challenge to Steven Goddard who he thought was too bullish earlier in May (on the WUWT blog) about the prospects for ongoing recovery of Arctic ice, and it seems like this was a fair point. [Steven Goddard did not take him up on the bet]

  206. Michael jennings
    Posted Jun 3, 2009 at 4:02 PM | Permalink

    Phil. #359
    That makes sense. Anyone know what the status of the switch over to the new sensor is?

    • Posted Jun 3, 2009 at 5:51 PM | Permalink

      Re: Michael jennings (#361),

      If you mean the F-17 it’s on-line, the calibration graph is here.

      • DeWitt Payne
        Posted Jun 3, 2009 at 8:57 PM | Permalink

        Re: Phil. (#362),

        If the latest graphs from Arctic ROOS are any indication, and I don’t know that they are, then cross calibrating F-17 with F-13 was a big mistake. According to Arctic-ROOS SSM/I data, Arctic ice area exceeded the 1979-2007 average from mid April to mid May and was on the order of 1 Mm2 higher than 2008 for the same time period. I don’t think so. The data from mid-2008 on is highly questionable when compared to other sources like JAXA, Uni-Hamburg and Cryosphere Today. F-13 was showing much higher (~3x) average differences with other sources for the last 18 months compared to the previous four or five years when compared to AMSR-E data. When I overlay CT or adjusted to CT Uni-Hamburg plots, the 2007 curve isn’t far off, but the 2008 curve after the minimum is only vaguely related to the other data and is much higher. 2009 starts out ok, but has diverged significantly since April with Arctic-ROOS being much higher.

        Speaking of CT, they posted recent data again today. It remains to be seen if there will be daily updates. It’s a real pain to blow up the graphs and digitize by hand to get the intermediate data when there are two week intervals between postings.

        • BarryW
          Posted Jun 4, 2009 at 12:12 PM | Permalink

          Re: DeWitt Payne (#364),
          Re: vg (#369),

          I hadn’t looked at Arctic-ROOS recently and was surprised to see 2009 within the 1 SD range, when the last time I looked it at been just on the edge. I gotta believe there is going to be a correction.

  207. Michael Jennings
    Posted Jun 3, 2009 at 7:29 PM | Permalink

    Yes that was what I was looking for Phil, thanks

  208. markinaustin
    Posted Jun 3, 2009 at 10:07 PM | Permalink

    anyone notice the new RSS data is out? with the exception of may of 2008, it was the coldest may anomaly since 1997, and (cherry picking here) slightly cooler tahn the temperature of May of 1980.

  209. AndyW35
    Posted Jun 4, 2009 at 12:51 AM | Permalink

    I don’t understand, on first thoughts how, if the F13 had started to drift, how they do match up after the drift started earlier this year, they should match up to the drifting point and then diverge. Perhaps they have worked out the rate of drift and corrected it back in the graph Phil links to? I am puzzled, perhaps I am missing some information.

    Regards

    Andy

  210. John Finn
    Posted Jun 4, 2009 at 4:17 AM | Permalink

    Re: #365

    with the exception of may of 2008, it was the coldest may anomaly since 1997,

    So further signs of “recovery” from the La Nina then.

  211. Chris
    Posted Jun 4, 2009 at 6:00 AM | Permalink

    Re: 367
    May 2009 had the coldest monthly anomaly in 11 months i.e. since June 2008, it was colder than the Mays of 1999 [albeit by a fraction] and 2000 which occurred during a greater overall La Nina event, and the anomaly was lower than for every month bar one in the 7-year/84-month period between Jan 2001 and Dec 2007. There’s no doubt ENSO has been coming out of La Nina and approaching El Nino; however, given this, the relatively low anomaly is if anything a sign of the relative slowness of the “recovery” of global temperatures thus far.

  212. vg
    Posted Jun 4, 2009 at 10:36 AM | Permalink

    If the Arctic-ROOS SSM/I data is correct after these corrections etc.. then NH ice has been in fact normal since mid last year. I do recall a major change sometime mid or later 2008 when its was adjusted dramatically downwards. maybe that was a mistake? Anyway if NORSEX maintains this data and it is correct (+ the antarctic data), there is definitely now physical proof of cooling/normalization of temperatures? It seems to be fitting in with global temp trends as well.

  213. AndyW35
    Posted Jun 4, 2009 at 11:51 PM | Permalink

    As well as satellite sensor issues the north pole webcam has stopped functioning perhaps, last image was from Sunday. Unless the website has an issue of course and they haven’t spotted it.

    Regards

    Andy

  214. Flanagan
    Posted Jun 5, 2009 at 12:42 AM | Permalink

    About the Arctic extent: I’m quite surprised by the comment… JAXA indicates it is now even lower than in 2008!
    2009 – 11306406
    2008 – 11347344

    • DeWitt Payne
      Posted Jun 5, 2009 at 8:56 AM | Permalink

      Re: Flanagan (#372),

      There were two days of increasing extent on 6/1 and 6/2 probably related to a change in algorithm at this time of year. It’s that uptick that wasn’t real and the extent and rate of change of extent are now returning to that observed prior to 6/1. It does look like the adjustment process is shorter this year than in previous years. Uni-Hamburg doesn’t seem to have the 6/1 spike problem, but we’ll have to wait about six weeks for them to post their June data.

  215. Michael Jennings
    Posted Jun 5, 2009 at 7:23 AM | Permalink

    About the Arctic extent: I’m quite surprised by the comment… JAXA indicates it is now even lower than in 2008!
    2009 – 11306406
    2008 – 11347344

    That would be an incredible drop (if it holds up) from an extent of 11523125 on 6/2 to 11347344 on 6/4. Seems like they could have misfigured one of those readings or else had an adjustment.

  216. Mike Bryant
    Posted Jun 6, 2009 at 12:13 AM | Permalink

    Phil.,
    I listened to the youtube video again,
    Gore said,“The entire north polar ice cap may well be completely gone in five years.”
    I had to listen to it eight or ten times since the translator stepped on the word “may” and the “well” sounds like “will”. I wonder how the translator rendered the phrase, anyone speak German?
    I corrected it at the other site as well.
    Thanks,
    Mike

  217. VG
    Posted Jun 6, 2009 at 4:53 PM | Permalink

    Thanks to the reliable honest Scandinavians:

    http://arctic-roos.org/observa…..-in-arctic

    was re-adjusted (from channel 13 to 17 )from LAST YEAR (when a massive “down adjustment” was made) It is now showing that a considerable part of 2008 was NORMAL (within 1SD) and is now showing that most of 2009 was completely NORMAL. Excuse the CAPS, Sorry… I do feel a bit over the top on this one.
    DMI concurs with NORSEX ice from what I can see

    http://ocean.dmi.dk/arctic/icecover.uk.php

    There is no significant sign of AGW anywhere now… ICE extent in 2010 and 2011 will be the nail in the coffin

    • AndyW35
      Posted Jun 7, 2009 at 12:36 AM | Permalink

      Re: VG (#376),

      ” ICE extent in 2010 and 2011 will be the nail in the coffin”

      I assume VG that you think there will be a big rebound of summer extent in those years, any particular reasons you think might increase the value?

      Regards

      Andy

    • DeWitt Payne
      Posted Jun 8, 2009 at 10:38 PM | Permalink

      Re: VG (#376),

      It is now showing that a considerable part of 2008 was NORMAL (within 1SD) and is now showing that most of 2009 was completely NORMAL. Excuse the CAPS, Sorry… I do feel a bit over the top on this one.

      Can you say “confirmation bias”.

      I don’t take NANSEN seriously any more. The SSM/I sensor on satellite F13, which they are currently using since the one on F15 failed catastrophically, has been sending back questionable data since at least mid 2008. I don’t have much hope for F17 data either since it’s apparently being cross-calibrated with F13. You can argue the relative accuracy of SSM/I vs. AMSR data, but at least the AMSR data is still self consistent from year to year, unlike the SSM/I data from F13.

  218. VG
    Posted Jun 6, 2009 at 4:57 PM | Permalink

    Re previous VG Correct link here apologies

    http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic

  219. VG
    Posted Jun 7, 2009 at 1:47 AM | Permalink

    Hi Andy
    Answer lies within these graphs

    http://www.ssmi.com/msu/msu_data_description.html#msu_amsu_trend_map_tlt

    see figure 7
    That’s why I think anyway for what is is worth.

  220. AndyW35
    Posted Jun 7, 2009 at 4:43 AM | Permalink

    Hi VG,

    Can you be more specific on what the answer is from those graphs? I’m a bit lost on the correlation to be honest. As the graphs in figure 7 show less fluctuation in recent years, where the biggest drops have been in summer ice extent, I’m not sure what I am supposed to be looking for.

    Regards

    Andy

  221. AndyW35
    Posted Jun 7, 2009 at 12:20 PM | Permalink

    Here’s a nifty JAXA type graph over a longer time period.

    Excluding 2007 and 2008 the graph shows

    1) Summer extent is roughly appropriate to March extent.
    2) March and September extents have been decreasing since 1980.

    Given that, even if we hit 6×106 km2 this year we will have only got back to the “normal” main sequence of decreasing values over time.

    • Posted Jun 7, 2009 at 1:00 PM | Permalink

      Re: AndyW35 (#381),

      Why does the data stop in early march?

      • AndyW
        Posted Jun 7, 2009 at 10:57 PM | Permalink

        Re: Phil. (#382),

        I assumed that was because that was the end date before their paper was published in that year, ie sometime in Spring/Summer 2008. I’m not sure when that was originally published though at the moment.

        VG, ok thanks for the brief outline for your hypothesis. If temps have been falling since 2002 then there must be some lag in a connected increase in ice extent as I cannot see that decrease yet on the graph I put up. It could be 2010/2011 though of course. We shall have to wait and see. Thanks for the link to the dauly temps.

        Regards

        Andy

  222. VG
    Posted Jun 7, 2009 at 5:55 PM | Permalink

    Andy: Just pointing out that global temperatures have been falling since 2002 Fig 7 sees TLT. I believe similar with SST (see below). BTW NANSEN now confirms current ice data
    http://wattsupwiththat.com/2009/06/07/nansen-corrects-sea-ice-data-sea-ice-extent-now-greater-normal-for-most-of-aprilmay/#more-8273 so in fact end of 2008 and most of 2009 were within 1SD.

    Now re temps: from R Pielke
    “He (Romm) ignores that since 2003, global warming (the accumulation of Joules) has stopped. An objective scientist [as opposed to a "clever (but cynical) analyst"] would report this scientific observation”

  223. VG
    Posted Jun 7, 2009 at 5:56 PM | Permalink

    re previous should be “since 2003″

  224. VG
    Posted Jun 7, 2009 at 8:27 PM | Permalink

    Phil: Statement not exactly spot one I agree but but pretty close… point being that the melting was completely exaggerated and is now fixed. RE Andy Perhaps a poignant reason why NH ice tending to return to normal here

    http://ocean.dmi.dk/arctic/meant80n.uk.php

    • BarryW
      Posted Jun 8, 2009 at 6:07 AM | Permalink

      Re: VG (#386),

      Even with the fix the present JAXA data is showing 2009 just about at the mean for 2003-2008 and it’s been falling so I don’t think you can be confident of a recovery this year.

  225. VG
    Posted Jun 9, 2009 at 1:49 AM | Permalink

    Phil Looks like I was right even with my slight exageration, after all
    NANSEN has once again readjusted upwards

    so in fact now 1/2 2008 and ALL (except 3 days) of 2009 within normal SD.
    As mentioned previously on ice extent thread, the drift of this satellite is down and will thus be constantly be re-adjusted most likely upwards to reflect reality. Sorry AGW your days are coming to an end LOL.
    Of cousrse I don’t expect anyone to believe NANSEN anymore they have now become your horrible enemies because it aint fitting the models LOL.. If NANSEN was going down im sure you’d take it very seriously

    • DeWitt Payne
      Posted Jun 9, 2009 at 3:04 AM | Permalink

      Re: VG (#390),

      This is why I don’t believe NANSEN:

      I’ve overlaid a a plot of the JAXA data on the same scale as the NANSEN data. Note that the data for 2007 is a near perfect overlap except at the minimum which is normal. Now compare the 2008 and 2009 data. The 2008 data isn’t too bad until after the minimum when it consistently runs high. The 2009 data is even worse except right at the peak. The April and May data for 2009 are 0.5 to 1.0 Mm2 higher for NANSEN. We know there’s a problem with F13. There are no reported problems with Aqua. This is an apples to apples comparison. Get the picture now?

      • Steve McIntyre
        Posted Jun 15, 2009 at 2:06 PM | Permalink

        Re: DeWitt Payne (#391),
        DeWitt, could I trouble you to include the url of the data as a note on the lower margin of your figure. I know that the context of the figures is explained up the thread, but there are enough provenance issues right now that it’s nice to embed the info in the figure itself.

        • DeWitt Payne
          Posted Jun 15, 2009 at 4:42 PM | Permalink

          Re: Steve McIntyre (#418),

          Done. I’ll try to remember to always do that in the future. Should I go fix the other images I just link to?

    • Posted Jun 9, 2009 at 9:38 AM | Permalink

      Re: VG (#390),

      il Looks like I was right even with my slight exageration, after all
      NANSEN has once again readjusted upwards

      so in fact now 1/2 2008 and ALL (except 3 days) of 2009 within normal SD.
      As mentioned previously on ice extent thread, the drift of this satellite is down and will thus be constantly be re-adjusted most likely upwards to reflect reality.

      No you’re being misled by Steve Goddard who doesn’t understand what he’s talking about and will misrepresent anything that suits his agenda. Nansen hasn’t ‘readjusted again’ the graph you cited is sea-ice area not extent, i.e. it’s a different quantity which was adjusted at the same time as extent. It’s not clear whether Nansen has switched to F17 or not, if they have there is no reason to expect further adjustments. By the way the satellite drift isn’t the issue it’s the sensor and recording system.

      Sorry AGW your days are coming to an end LOL.
      Of cousrse I don’t expect anyone to believe NANSEN anymore they have now become your horrible enemies because it aint fitting the models LOL.. If NANSEN was going down im sure you’d take it very seriously

      Of course extent is going down even on Nansen, however their data is now inconsistent with data from NSIDC (SSMI) and ASMR-E which is a concern.

  226. VG
    Posted Jun 9, 2009 at 4:33 AM | Permalink

    And this why I believe NANSEN
    http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png 6/09/09
    go and compare this with 2007 and 2008 same date. The ACTUAL ice extent.

    • DeWitt Payne
      Posted Jun 9, 2009 at 11:30 AM | Permalink

      Re: VG (#392),

      Cryosphere Today has removed all SSM/I images from 2009 from their side by side comparison applet. That should tell you something. Here are links to Uni-Bremen Aqua images from 5/1/2009 and 5/1 2008 and 5/1/2007 when NANSEN data claims that extent is over 1 Mm2 (~10%) higher in 2009, and 2008 being lower than 2007.

      JAXA extent
      5/1/2007 12627813
      5/1/2008 12865156
      5/1/2009 13135156

      The images show a clear progression of extent from 2007 to 2008 to 2009, but 2009 is only somewhat larger than 2008 because increases in the Barents Sea in 2009 are reduced by lower extent in the Bering Sea and Hudson Bay.

  227. AndyW35
    Posted Jun 9, 2009 at 11:41 AM | Permalink

    Here’s a graphical representation of those years for the lazy
    reference

    Regards

    Andy

  228. AndyW35
    Posted Jun 9, 2009 at 12:25 PM | Permalink

    I have to agree with Dewitt on this, it’s notoriously hard to tell close extents from the images because you have to mentally split the image into segments and then you could always be “favouring” one segment rather than the next depending on where your initial bias lies. Geographical images such as the above should only be used for showing a comparison of locational melting in comparison to other years for interest sake, not absolute values. The graphs are better at telling you that.

    I seem to think you have an anti AGW agenda here VG, and it’s a bit misplaced I think. I am moderately pro AGW, pro scientist, but if we got a massive decrease over last year then I wouldn’t be saying it is due to AGW, I would just be saying that will be interesting to watch the explanation! And same if it leaped back up to a lot more, what is the explanation? Watching ice melt is certainly more interesting than my day job which is working at a bank. Which probably tells you something how my career path went wrong rather than anything else :D

    Regards

    Andy

  229. markinaustin
    Posted Jun 10, 2009 at 9:17 PM | Permalink

    last few days have been good to the ice extent over at IJIS….seems to be slowing rapidly. could it be that a lot of the thinner first year ice melted but that 2009 will end up fairly strong because of 2008’s good showing? i hope so!

    snip – OT

  230. AndyW35
    Posted Jun 11, 2009 at 11:25 AM | Permalink

    I think it’s just cold up there as Chris indicated it might well be. The ice in the Barents has not dispersed as much as it should have done, there is not as much free sea to north of Alaska and Canada in the Beaufort as last year and of course the cold water temps in the Barents has held back the melt there. On the other hand there are a lot of ice free areas and the Atlantic side looks very fragmented. I still think the NE passage looks a cert this year as I have said all along. NW as well for 2 years on the trot a circumnavigation is do-able. That’s my bet. Shall we hire a yacht and become famous.

    This really means nothing yet of course, July is the start of when things get interesting. I still think a slight increase in minima this year to fit above 2008, but who knows. The last 2 years have not fitted in the pattern for the last 30.

    Regards

    Andy

    PS Thanks to Phil for his contributions to a CO2 thread on another forum. Excellent reading. Although I agree with Phil I posted a reply on the other side of the fence which I think Phil will have a hard time contradicting ;) Great reading though.

  231. See - owe to Rich
    Posted Jun 11, 2009 at 3:59 PM | Permalink

    I’m glad if the extent loss has slowed up a bit. Because to my eye, the open water already in the NW passage is “unprecedented”. Perhaps I haven’t looked at enough different years, but from what I have looked at, I can’t see anything to compare.

    Views? (Better still, knowledge?)

    Rich.

  232. Bill Illis
    Posted Jun 11, 2009 at 7:00 PM | Permalink

    See – owe to Rich,

    The Ocean currents between Greenland and North America were very strong this winter and it literally pulled the sea ice out of the Davis Strait and the eastern end of the NW Passage into Baffin Bay.

    This open water has been there for a few months already.

  233. Chris
    Posted Jun 12, 2009 at 4:10 AM | Permalink

    Bill Illis,
    Is it CO2 rich?

  234. BarryW
    Posted Jun 12, 2009 at 12:08 PM | Permalink

    Here’s this weeks JAXA extent: 2009 is just behind 2003 and 04

     
    year           extent       weekly change
    2003         11.19000            -0.41422
    2004         11.01391            -0.28828
    2005         10.66375            -0.40172
    2006         10.62297            -0.40922
    2007         10.82875            -0.29438
    2008         10.82766            -0.62531
    2009         10.95828            -0.35250

  235. markinaustin
    Posted Jun 12, 2009 at 3:06 PM | Permalink

    yeah…the trend the past 4 days has been a serious slowing of meltoff…..at this rate, another week and 2009 could be number 1, but i am not counting on that.

    • BarryW
      Posted Jun 12, 2009 at 6:06 PM | Permalink

      Re: markinaustin (#403),

      Right at the algorithm change over there is an abrupt decrease in loss followed by a equally large increase. This happens in all the years. After that it moderates back to a more consistent variance. The loss rate seems to have flattened in the last few days compared to before the change over. I think there is another 20 days to a month before we might see any dramatic change this year based on the graph.

  236. VG
    Posted Jun 14, 2009 at 1:44 AM | Permalink

    its all here http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png AGW = about to die LOL

  237. AndyW35
    Posted Jun 14, 2009 at 9:58 AM | Permalink

    Bugger … from the north pole web cam page, as feared, technology has failed

    “The North Pole web cam stopped transmitting images on May 31. Investigations indicate the camera itself is still functional but is failing to transmit images. The adjacent instrumentation, with a different data transmission system, is still functioning and transmitting data. Although we are unable to repair the web cam transmission problems remotely, there remains a slim possibility that the camera could spontaneously resume transmissions without our intervention”

    That’s a shame, although not very scientific I did like watching on the ground what was happening to give a real life backdrop to a squiggly chart or colourful graphic. Hopefully the glitch will sort itself out and I can watch the meltponds come and go. Beats Next top model singsong talent show anyhow.

    Regards

    Andy

  238. John M
    Posted Jun 14, 2009 at 10:30 AM | Permalink

    Investigations indicate the camera itself is still functional but is failing to transmit images.

    Wow, a web cam that’s not transmitting but is still “functional”.

    This truly is a nuanced field.

  239. Neven
    Posted Jun 14, 2009 at 1:14 PM | Permalink

    Not transmitting images. Read.

  240. John M
    Posted Jun 14, 2009 at 2:25 PM | Permalink

    Sorry. I thought the “function” of a web cam was to transmit “images”. Maybe it’s supposed to transmit a baseball game?

  241. BarryW
    Posted Jun 14, 2009 at 2:59 PM | Permalink

    JAXA hasn’t been updating since the 11th. Coverage loss or vacation?

  242. AndyW
    Posted Jun 14, 2009 at 11:07 PM | Permalink

    Perhaps that is functional but not posting Barry ! :D

    There does seem to have been an unfortunate rash of technical problems this year compared to last.

    Regards

    Andy

  243. Shawn Whelan
    Posted Jun 15, 2009 at 10:02 AM | Permalink

    So why such a large difference in ice extant between arctic roos and NSIDC?

    http://www.nsidc.org/arcticseaicenews/

    • DeWitt Payne
      Posted Jun 15, 2009 at 10:51 AM | Permalink

      Re: Shawn Whelan (#412),

      Because Arctic ROOS has screwed up again very much like they did last year. You can overlay JAXA and NSIDC extent graphs and see that they are in reasonable agreement. Not so with Arctic ROOS. See my post above.

  244. John G. Bell
    Posted Jun 15, 2009 at 10:39 AM | Permalink

    Shawn Whelan,
    They look close to me. What am I missing?

  245. Shawn Whelan
    Posted Jun 15, 2009 at 11:47 AM | Permalink

    I can’t overlay JAXA, it isn’t updating.

    • DeWitt Payne
      Posted Jun 15, 2009 at 11:53 AM | Permalink

      Re: Shawn Whelan (#415),

      I’m using plots in excel from downloaded data and copying them to Paint. Then you can squeeze or stretch them to match the size of the internet image. You do have to clear any color from the background of the plot, though. JAXA may not be updating, but the historical data can still be downloaded using the button on the page with the graph.

  246. Shawn Whelan
    Posted Jun 15, 2009 at 1:19 PM | Permalink

    Goddard and Watts say Arctic Roos is correct.

    http://wattsupwiththat.com/2009/06/07/nansen-corrects-sea-ice-data-sea-ice-extent-now-greater-normal-for-most-of-aprilmay/

  247. Chris
    Posted Jun 15, 2009 at 3:03 PM | Permalink

    Amsu temps are back up and perhaps surprisingly depressed given the recent warming over large areas of the tropical oceans (shift towards El Nino)

    http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+002

    Also I note that there is a lack of warm anomalies in recent days over the Arctic on the NOAA reanalysis maps:

    http://www.cdc.noaa.gov/map/images/rnl/sfctmpmer_01b.rnl.html

    I wouldn’t be surprised if Arctic ROOS aren’t so far off the mark and the melt continues to be relatively slow overall.

  248. Chris
    Posted Jun 15, 2009 at 4:58 PM | Permalink

    Just had a quick play-around on Excel.
    Couple of interesting points:
    – Firstly, for both RSS and UAH, the North Polar region (~60-82.5N) appears to be currently the coldest since 2002 on both 18- and 24-month (prior) moving averages.
    – Secondly, it could yet be possible to get a negative global temp trend for this decade. Using UAH global data, I filled in the rest of this year’s anomalies as 0 (June), 0.04, 0.08 etc up to 0.24 for December. And got a negative trend from Jan 2000 to Dec 2009.
    [ Note the equivalent global temp anomalies for 1997 were -0.006 (June), 0.085, 0.099, 0.095, 0.139, 0.195, 0.307; and 1997 was earlier onset/stronger El Nino

    http://www.longpaddock.qld.gov.au/SeasonalClimateOutlook/SouthernOscillationIndex/SOIGraph/2009.gif ]

    • DeWitt Payne
      Posted Jun 15, 2009 at 9:50 PM | Permalink

      Re: Chris (#421),

      The AMO index has been negative from January to May, although May is just barely negative. That implies a lower flow rate of warm tropical waters to high latitudes.

      Unless things turn really bad in the next two weeks, it looks like the Spring (AMJ) average JAXA extent could actually have a positive slope for 2003 to 2009.

  249. BarryW
    Posted Jun 15, 2009 at 9:24 PM | Permalink

    JAXA finally updated and 2009 is just behind 2004 in third place

  250. Posted Jun 16, 2009 at 4:41 AM | Permalink

    You can match AMSR-E derived arctic sea ice extent with the SMM/I derived sea ice extent using a simple linear regression for the period 2002-2007.

    This enables pre-2002 SMM/I-SMMR sea ice extent to be “corrected” to make it compatible with AMSR-E.

    Seasonal analysis of the resulting daily time-series 1978-now is done using R’s stl function. The result is (up to June 11 2009):

    The next couple are years are going to be very interesting.

  251. markinaustin
    Posted Jun 16, 2009 at 4:52 PM | Permalink

    now it is BARELY ahead of 2004, in 2nd place!

  252. Flanagan
    Posted Jun 17, 2009 at 5:51 AM | Permalink

    Ahead of 2004? Not quite…

    6/16/2009 10727188
    6/15/2008 10664531
    6/16/2007 10574844
    6/16/2006 10337969
    6/16/2005 10487188
    6/15/2004 10806250
    6/16/2003 10939844
    6/21/2002 10615781 this is the closest date we got

    Actually, the gap with 2007/2008 is closing…

    • BarryW
      Posted Jun 17, 2009 at 7:52 AM | Permalink

      Re: Flanagan (#426),
      Re: markinaustin (#425),

      Whether it’s closer to 2007/8 today or not doesn’t really tell you anything, it was moving away a few days ago. Just random noise in the data. This time of year the change in extent is getting smaller so all years are getting closer to the average. In about a week the spread between years opens up. 2007 started diverging from the pack in about two weeks from now but 2008 took a couple of months more. Present numbers are like watching the Derby on the back stretch: doesn’t tell you the finish order.

      • DeWitt Payne
        Posted Jun 17, 2009 at 9:47 AM | Permalink

        Re: BarryW (#427),

        This time of year the change in extent is getting smaller so all years are getting closer to the average.

        You mean getting larger rather than smaller don’t you? While the loss rate flattens out some at this time of year, it still averages about -50,000 km2/day. Maximum average loss rate happens late July to early August at about -80,000 km2/day. The curves appear close together because the slope is high. Plotted as an anomaly, there isn’t all that much difference in the variability from any other time of year except near the time of maximum loss rate where 2007 and 2008 have had a substantial effect on the standard deviation for the 2002-2008 average.

        I’ll post the extent rate and extent anomaly plots later.

        • BarryW
          Posted Jun 17, 2009 at 12:03 PM | Permalink

          Re: DeWitt Payne (#428),

          I misspoke (miswrote?). The differences in the rate of change between years are smaller, not the magnitude. The differences in extent have also narrowed between 2009 and the other years.

        • DeWitt Payne
          Posted Jun 17, 2009 at 12:55 PM | Permalink

          Re: BarryW (#429),

          Here are my anomaly plots: Rate Extent. The rate anomaly is calculated from the EWMA smoothed daily difference (alpha = 0.1), Mean and standard deviation from the 2003 to 2008 averages. I haven’t tried any statistical test, but eyeballing the variation in standard deviation, it’s not at all clear to me that there is a significant difference from day to day for most of the year, considering the small number of data points for each day. So the apparent shrinkage in the range of the difference may be more apparent than real. I don’t think we have enough data to be sure. Someone way better at statistics than I would have to determine how to test it. I could put it in something like an Xbar R control chart, but control chart statistics are designed for prospective not retrospective analysis.

        • BarryW
          Posted Jun 18, 2009 at 10:41 AM | Permalink

          Re: DeWitt Payne (#430),

          The first thought I had on seeing your charts is where there is a large change in your three sigma lines. Since there are so few data points the SD is sensitive to the outliers (2007-8) and the SD balloons where they “leave the pack” so to speak. So without those two the SD is probably uniform over the year.

  253. AndyW35
    Posted Jun 17, 2009 at 2:33 PM | Permalink

    At this point of the year the locations ice free might be more interesting than the total amount left. In this respect 2009 follows 2007 more than 2008. Does this mean a bigger potential drop like 2007? No, it’s just interesting in it’s own sake, you can’t read anything into it. We’re just treading ice, sorry water, until July at the mo in relation to the minima.

    I still think my NE passage being open is a dead cert though, and confident about the NW as well for another year of circumnavigation. If only I had a boat. I’d be Sir Andy by the end of the year !
    :D

    Regards

    Andy

  254. markinaustin
    Posted Jun 17, 2009 at 6:04 PM | Permalink

    any thoughts on this?

    http://science.nasa.gov/headlines/y2009/17jun_jetstream.htm?friend

    • Shawn Whelan
      Posted Jun 18, 2009 at 12:53 PM | Permalink

      Re: markinaustin (#432),

      NASA has been wrong every step of the way predicting this sunspot cycle. I expect that trend to continue.

      • See - owe to Rich
        Posted Jun 18, 2009 at 3:22 PM | Permalink

        Re: Shawn Whelan (#436), firstly, why on earth did mark-in-austin use this thread. Wot’s wrong with Svalgaard #8 or whatever?

        Anyway, Shawn, you do seem to be a real sceptic. Yes, NASA have been wrong, and Svalgaard too, but now they have an observable with a strong correlation to activity, so I don’t think they should be dissed on this until after the data come in.

        Heck, David Archibald predicted that now was the time for solar minimum 2 years ago, so if the Sun is about to turn up, an itty bit, should we be surprised?

        But the effect of this long solar cycle will be felt for many years to come…

        If only it could affect Copenhagen December 2009!

        Rich.

  255. Michael Hauber
    Posted Jun 17, 2009 at 11:04 PM | Permalink

    Do we need more ways to compare JAXA extent for various years?

    Average loss for June 17 is 63,794 km2. So Based on figures as of today, the number of hours melt at the average rate to equal the difference between 2009 and each year (as at June 17) is:

    2003: -88 hrs (2003 had more ice)
    2004: -12 hrs
    2005: 84 hrs (2005 had less ice)
    2006: 138 hrs
    2007: 49 hrs
    2008: 42 hrs

    No correction made for leap years.

    • DeWitt Payne
      Posted Jun 18, 2009 at 8:52 AM | Permalink

      Re: Michael Hauber (#433),

      I don’t like time behind or ahead as a comparison for sea ice because it will vary more with the rate than the difference in magnitude. When rates are high, the time difference will be small and vice versa. It’s the opposite of cars on a road race course where time difference is the preferred measure rather than than distance because distance varies with speed for cars with equal performance and driver skill. The cars will appear to bunch up in a corner and stretch out on the straights, even though the time difference is approximately constant.

  256. Steve McIntyre
    Posted Jun 18, 2009 at 5:41 PM | Permalink

    Continued at http://www.climateaudit.org/?p=6316

  257. Posted Mar 29, 2009 at 8:18 PM | Permalink

    Re: See – owe to Rich (#740),
    This links back.

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