Discrepancies In Sea Ice Measurements

By Steve Goddard

Over the last few weeks I have been tracking what is becoming a large discrepancy between various Arctic sea ice measurements. NSIDC graphs show almost no difference between 2010 and 2007.

http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

By contrast, DMI graphs show nearly one million km² more ice in 2010.

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

Here is the graph above zoomed:

The video below shows 2010 started to diverge in mid June, and 2007 started to diverge in early July. At this point we have a major discrepancy between the two.

DMI uses 30% concentration ice and NSIDC uses 15%, which affects absolute values . But the relative year over year numbers shouldn’t vary very much.

The image below shows NSIDC August 03, 2010 compared with the same date in 2007. Green areas have more ice in 2010. Red areas had more ice in 2007.

The NSIDC maps show 7.5% more ice in 2010 than 2007, but their graph shows less than 3% difference.

The period from August 3 through August 15 was when most of the ice compaction occurred during 2007. Unless something unexpected happens with winds in the Arctic, NSIDC graphs should start to diverge from 2007 – more like the DMI graph.

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160 thoughts on “Discrepancies In Sea Ice Measurements

  1. don’t worry, something “unexpected” will happen ….. or maybe it is to be expected. The Alarmists will ensure that the data fits the narrative.

  2. It could simply be differential melt of the two populations of ice. Imagine thicker older ice which melts more slowly resulting in a slow reduction in the > 30% coverage areas, whereas at the margins the 15% < x < 30% ice population is made up of thinner, younger ice. Late season, one could easily imagine differences between these populations.

  3. Until the 5th, when the Long range weather forecasts e.g. http://weather.unisys.com/gfsx/9panel/gfsx_500p_9panel_nhem.html say the La Nina Pattern is set to go “On” just like in 2007. Till the end of the Forecast (Aug 10th) at least. But the CTI index suggests for about 2 months.
    Surprise ! !
    PS: perhaps the reason for the “Discrepancy” is the “True” NSIDC map is the background for the Arctic Buoy site (be sure to page down, top area is blank): http://iabp.apl.washington.edu/maps_daily_nsidcice.html
    … looks like Moths got at it. Presumably some of the low concentration areas are counted as “open” for 2010. But this happened in 2007 in June: then the La Nina winds compacted the ice & 2007 looked better on DMI.
    By the way, would you post my FULL Sea Ice Outlook ? — the parts about the La Nina were censored. Like 70% of the text. There I show the various indexes & the apparent time lags in 2007 for standard (9 weeks) CTI (6 weeks), etc. Looks like CTI won.
    PS sorry for the duplicate post on your color change post.

  4. The JAXA numbers also appear to be more inline with the DMI numbers (noting their different cutoffs of 15% vs 30%).
    I too, noticed the NSIDC trend line was diverging from the JAXA trend line several days ago.
    I don’t think the following is in your sea ice links, but I could be wrong;
    http://nsidc.org/data/seaice_index/images/daily_images/N_daily_concentration_hires.png
    taken from this NSIDC link;
    http://nsidc.org/data/seaice_index/
    It shows the daily concentration image (NOTE: it shows zero concentration but does not show 0% < concentration < 15% data, in other words, it is their 15%+ concentration map).

  5. I only trust the Scandinavians on this one. This seems like a clear case of attempted fraud as is the SST data/graphic manipulations by the American NOAA/NSDC ect.. They are doing a tremendous disservice to the perception of American Science (must say same for British and Australian Meteorological services as well, unfortunately). There is a litany of ice data graphics manipulations since 4 years ago by these people here.
    http://mikelm.blogspot.com/2007/09/left-image-was-downloaded-from.html
    someone might care to add this one for the record….
    When the AGW comes crashing down this year its going to be real bad news for these people

  6. NSIDC counts meltwater pools on top of ice as open water, I’ll bet. Since the NSIDC agenda is to estimate when “all the ice will be gone from the arctic”, this is understandable, as meltwater ponds have a corrosive effect on ice in general. DMI, on the other hand, only seems to have an agenda of measuring the ice, even if it is submerged under meltwater pools.

  7. The warmist could not accept any NH ice even close to 2005-2006 the whole thing will crash that is why NSCDC cannot accept DMI graph.

  8. I asked this on the last Sea Ice update thread, but didn’t get any response. Has any explanation been offered for the large discrepancy between the Arctic Ice Area numbers for CT and Nansen ArcticROOS? CT is quoting less than 4.4mkm2, while Nansen’s graph is indicating more than 5mkm2 and the gap appears to be widening.

  9. The NSIDC maps show 7.5% more ice in 2010 than 2007, but their graph shows less than 3% difference.
    Another case of ‘rotten ice?’
    Or maybe it’s just ice termite-ridden?
    :o)

  10. There is also a discrepancy between JAXA and NSIDC. NSIDC reports a loss of 603,770 km^2 of ice from July 29 to August 2, and JAXA reports much less 355,469 km^2 during that same time period.
    NSIDC
    20100729 = 7.1605200
    20100730 = 7.0599500
    20100731 = 6.8812300
    20100801 = 6.7729500
    20100802 = 6.5567500
    JAXA
    7,086,719
    7,008,750
    6,922,031
    6,819,531
    6,731,250

  11. NSIDC has their monthly update out:
    High-resolution (250-meter) visible imagery from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) sensor vividly shows the loss of the old, thick ice. A chunk of old ice has broken away from the main pack and come to rest along the north coast of Alaska, east of Point Barrow, where it has begun to melt in the warm shallow shelf waters. While cloud cover obscures some areas, it is clear that the old ice floe has broken up into many smaller floes. Whether this old ice will completely melt out by the end of summer will depend to some extent on weather conditions. However, smaller floes melt more easily than consolidated ice. This behavior is becoming more typical of the ice pack as the ice thins.
    Barrow! Barrow played an essential in previous analyses here. What does this event at Barrow Point tell us about the rest of the Arctic? [Snip. You know why. ~db stealey, mod.]

  12. 899 says:
    August 4, 2010 at 3:43 pm
    The NSIDC maps show 7.5% more ice in 2010 than 2007, but their graph shows less than 3% difference.
    Another case of ‘rotten ice?’
    Or maybe it’s just ice termite-ridden?

    No just Steve doing his pixel counting without allowing for the projection used, same as usual.

  13. mikelorrey says:
    August 4, 2010 at 3:30 pm
    The DMI Graph of 80N is close to freezing, and is staying put.
    The Aug3 NOAA polecam showed frozen pond and some new snow.
    NOAA/NSIDC and it’s subsidiaries are digging themselves a hole.
    Congress will be less than thrilled about that.
    Ships are not the only things capable of getting stuck in the pack ice.

  14. If weather conditions turn into those 2007 experienced there is a very good chance of a new minimum extent record. And that after 5 weeks of weather conditions that are adverse to ice melting, with all those clouds, lower temperatures and the Beaufort Gyre and Transpolar Drift Stream stalling completely (reversing even).
    Despite those adverse conditions during the most important phase of the melting season, the ice looks in a terrible state and could reach a new record minimum extent, if weather conditions switch back again. Amazing, really.
    If the Arctic shows another ‘recovery’, it will be because very, very thin ice managed to get spread out enough and survive long enough for the cold air to come and let the sea water between the floes freeze up again.
    Come in, CryoSat-2. We need your data.

  15. Do NSIDC and the other agencies publish standards for measuring ice? Has anyone published a revised set of standards recently? Can these standards be checked against the graphs?

  16. Joe Bastardi said around mid July 2010:
    “The coming drop of global temperatures over the next year, to levels not seen since the 1990s, should put to an end to the AGW argument for good except for the most radical elements…………… Once the Atlantic, still warm, goes into its cool stage in 10-15 years, global temps will fall even further, back to where they were in the 1970s.
    The recovery of the northern ice caps will become more obvious in a two-steps-up, one-step-back fashion, but the Southern Hemisphere ice will retreat back to near normal. Overall global ice is right on top of normal and has had no change in the past 30 years. ”
    http://www.accuweather.com/world-bastardi-europe-blog.asp?partner=accuweather
    http://pgosselin.wordpress.com/2010/07/17/will-2010-stay-hot-and-joe-bastardi-return-to-1970s-cold/

  17. Worry not Steve, 2010 is showing no great change from the general downtrend over the past few years. These little differences may be of interest if you’re looking a the variations of sea ice within a specific week, month, or season, but these little variations and differences are insignificant when talking about bigger picture of climate. 2010 falls right in line with the general downtrend in year-to-year Arctic sea ice that we’ve been seeing for several decades as well as the accelerated downtrend we started seeing in 2007. If this trend is going to reverse, as the AGW skeptics would like to contend, then I surely would like to know:
    1) By what physical known mechanism will this reversal take place (i.e. what natural cycle will be swinging back the other way) GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.
    2) What is the anticipated year that we will see this uptrend begin?
    3) Will this be a “spiral” up, or should we anticipate a bee-line back to 8 million sq. km. summer minimums?

  18. Haven’t they learned that we’re watching this stuff daily and they cannot get away with fudging ANYTHING?

  19. Perhaps a person well informed on this topic with appropriate credentials could ask the director of NSIDC what his agency is doing differently this year from 2007 that leads to results that are so inconsistent with their results in 2007 and with other major systems in 2010? Perhaps they are not aware of the discrepancies? If they are aware one would think they also know why.
    Or (sarcastically) is all of this proprietary information that the agency is contracted with entities across the globe not to disclose?

  20. We are not really talking about “sea ice measurements”. We are talking about sea ice estimates. Otherwise, the divergences could not possibly be so large.

  21. Charles Wilson says:
    August 4, 2010 at 3:27 pm
    PS: perhaps the reason for the “Discrepancy” is the “True” NSIDC map is the background for the Arctic Buoy site (be sure to page down, top area is blank): http://iabp.apl.washington.edu/maps_daily_nsidcice.html
    … looks like Moths got at it. Presumably some of the low concentration areas are counted as “open” for 2010. But this happened in 2007 in June: then the La Nina winds compacted the ice & 2007 looked better on DMI.
    ____________________________________________________________
    HMMmmm the satellite photo seem to shows a heck of a lot less open water than http://iabp.apl.washington.edu/maps_daily_nsidcice.html does. However I may be confusing clouds with ice.

  22. Some of you guys seriously think that there is fraud going on here?
    ~shakes head in wonder and despair~

  23. DMI and NSIDC measure two different things: one is 30 per cent and the other is 15 per cent.
    re JAXA, they have always been different than NSIDC. Look at the records, for example: NSIDC has a lower record minimum than JAXA by over 100,000 square kilometres. They use different algorithms for counting the ice, so these differences are to be expected.

  24. What the ice graphs are telling me is that the ice is more intact and consolidated this year. 15% extent is down but 30% extent is up. Ice area is leveling off nicely. It just means that we have about as much ice now as we had in 2009 but that it is more consolidated and wasn’t broken up so much by storms/wind/wave as much as previous years.
    That temperature graphic is already showing an area below 0C near the pole. The ice area should begin to level out now. Iceland is picking up 6.5 minutes of darkness per day now and the night is already nearly 6.5 hours from sunset to sunrise.
    So far it looks like we are sitting good for a really solid icepack next year.

  25. More Arctic ice news, nice. 🙂
    The only thing I like more than Arctic ice news right now is news about Brett Favre. 😉

  26. R. Gates says:
    August 4, 2010 at 4:30 pm
    I believe the onus is on you to prove your idea that the recently observed slow decline in Arctic ice is due to AGW or human produced CO2 or whatever you are want to call it these days. You also need to provide proof to viewers here why the observed slow increase in Antarctic ice is also due to AGW.
    Put up the proof or stop the tedious “caused by AGW” you continually post on this website.

  27. David Gould says:
    August 4, 2010 at 5:29 pm
    “Some of you guys seriously think that there is fraud going on here?
    ~shakes head in wonder and despair~”
    It isn’t difficult to understand. Many here are so used to seeing intentionally manipulated data in regards to the climate, that the response is expected. In this particular instance, I’m willing to give the benefit of the doubt. But even knowing they do measure 2 different things, the discrepancy shouldn’t be that great when measuring the difference between now and 2007. Given the NSIDC’s graph and map don’t match, I’d say the grapher and the mapper are not on the same page. Oddly, though just by eyeballing, even if the graph reflected the map’s ice area, I think the year to year comparison would still be too great of a difference to reflect reality. But that’s just eyeballing.

  28. While sea ice extent is the measure of choice (and for good reason), sea ice area is of some predictive value. Recently, the cloudy Arctic has minimized total melting. See the area graphs here:
    http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic
    and here:
    http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Area.png
    Apparently, some winds has been crowding the ice a bit, but this bodes well for the Arctic sea ice extent over the next few weeks, especially the NSIDC plot. All these sources are legit and their discrepancies typically reconcile pretty quickly.

  29. Ed Reid says:
    August 4, 2010 at 5:05 pm
    We are not really talking about “sea ice measurements”. We are talking about sea ice estimates. Otherwise, the divergences could not possibly be so large.
    They are measurements taken from satellite. That is why it’s odd they aren’t close to the same.
    mikelorrey made an interesting comment that “NSIDC counts meltwater pools on top of ice as open water, I’ll bet” which could be the explanation. But I don’t know for sure.

  30. David Gould says “Some of you guys seriously think that there is fraud going on here?” Bless you David, for your naivete. I sincerely hope your assumption (that the discrepancy can be legitimately explained) is correct.
    But given the shenanigans revealed by Climategate E-mails, Jim Hansen’s ‘adjustments’ of NASA’s GISS data, and Phil Jones ‘adjustments’ of CRUTEM data, why wouldn’t some of us suspect Mark Serreze might ‘adjust’ NSIDC data to support his predicted “Arctic Ice Death Spiral”? By their own admission, all of these ‘climatologists’ share a common agenda. Important climate data is almost routinely manipulated to fit pre-determined outcomes, so why wouldn’t one suspect that it may be happening here?
    Remove these foxes from the climate data hen house! Replace them with objective scientists who don’t ‘adjust’ data to fit agendas or psychic prognostications. Then we wouldn’t have to be conspiracy theorists.

  31. stevengoddard says:
    August 4, 2010 at 5:28 pm
    Gail
    The satellite photo you linked was from July 5.
    ______________________________________________
    Weird.
    If you click on the date on the right hand corner you get a calender and can up date. I am surprised the link was not update too.
    HMMmmm I tried it again and the link still did not update to the map I was actually looking at – July 31 2010
    I figured it out. Try this: http://ice-map.appspot.com/?map=Arc&sat=aqa&lvl=6&lat=74.571668&lon=-139.120367&yir=2010&day=212

  32. The rotted/alarmingly thin ice hypothesis forecasts are not panning out. The hypothesis doesn’t have supporting evidence.
    “If it disagrees with experiment it’s wrong.”
    ~Richard Feynman

  33. David Gould says: fraud? ~shakes head in wonder and despair~
    August 4, 2010 at 5:29 pm
    I have the same feeling. Many folks seem to think that someone is in charge. Who? Anyway, those calling fraud ought to spend a few days writing out a very detailed plan as to how they would accomplish what these agencies and their people are trying to do. Start with the equipment you will need. Then the people to do it. Then begin with what you would do tomorrow morning, and tomorrow afternoon. Keep repeating. Check back in a couple of weeks and let the rest of us know how you are doing.

  34. Amino Acids in Meteorites says:
    August 4, 2010 at 6:39 pm
    The rotted/alarmingly thin ice hypothesis forecasts are not panning out. The hypothesis doesn’t have supporting evidence.
    “If it disagrees with experiment it’s wrong.”
    ~Richard Feynman

    Ha! No Falsification Criteria will be admitted to. AGW admits to no falsification. It can’t be falsified and never will be.
    Its death – apart from a few die hard adherants who will never give in – will be induced by the general popular realisation that it is a pseudo scientific dogma.

  35. Perhaps this is a case of ‘noble cause corruption’ made manifest or just an honest difference of opinion. For a real comparison with 2007 data, it is necessary to demonstrate that they are now using the very same measurement criteria that they used to collect that 2007 data.

  36. The only useful plot is arctic plus antarctic anyway.
    There’s clearly something to do with tilt or the like which means that when the antarctic is at historic highs the arctic is low. Presumably the opposite is also true?
    It’s just a media war now. Forget the science.
    My ignorant bet when polled at this site months ago was for ‘more ice than 2008 but less than 2009’ at September minimum.
    Time will tell whether I’ll be right or not.
    Although I’m wondering which graphs will be used to make the decision!!!!

  37. The NSIDC maps show 7.5% more ice in 2010 than 2007, but their graph shows less than 3% difference.
    NSIDC has to handle the polar stereographic projection correctly, unlike bloggers that just eyeball an image or count pixels. I’d be very surprised if someone proved that the National Snow and Ice Data Center was doing this incorrectly, but you’re welcome to try and surprise me (and NSIDC).
    Polar stereographic projections are conformal (preserves angles), but not isometric (preserves distances) or area-preserving.
    http://nsidc.org/data/nsidc-0051.html

  38. Stephan says:
    August 4, 2010 at 3:29 pm
    I only trust the Scandinavians on this one. This seems like a clear case of attempted fraud as is the SST data/graphic manipulations by the American NOAA/NSDC ect.. They are doing a tremendous disservice to the perception of American Science (must say same for British and Australian Meteorological services as well, unfortunately).

    Looks like the Germans (Universität Bremen, Universität Hamburg) are in on the fraud, along with the Americans, British, Australians and Japanese:
    http://img689.imageshack.us/img689/7534/iceextn8410.png
    http://img412.imageshack.us/img412/7529/arclatestlarge201008030.png
    When the AGW comes crashing down this year its going to be real bad news for these people
    Yes, there will be plenty of explaining demanded of scientists if the Arctic summer minimum is only less than 2009 or 2008, but not 2007. “Dr. Maslowski predicted ice free Arctic summers by 2016 ± 3 years, how do you account for the fact that the Arctic is not ice free in 2010 ?” confused dilettantes will demand.

  39. John F. Hultquist says:
    August 4, 2010 at 6:57 pm
    David Gould says: fraud? ~shakes head in wonder and despair~
    August 4, 2010 at 5:29 pm
    I have the same feeling
    ===============================
    Are you the same person? You asked for a detailed plan, however, and here it is:
    1 – Get computer and turn on
    2 – All I need is me
    3 – Adjust data to fit model
    4 – Repeat until sky falls in
    Just-ice will be done!

  40. Rhys Jaggar says:
    August 4, 2010 at 7:30 pm
    The only useful plot is arctic plus antarctic anyway.
    There’s clearly something to do with tilt or the like which means that when the antarctic is at historic highs the arctic is low. Presumably the opposite is also true?

    This should help:
    http://www.robertb.darkhorizons.org/seaice.anomaly.Ant_arctic.jpg
    Apparently, the Arctic Sea Ice was higher than the Antarctic until they crossed paths in mid 1993.
    Right about the time the Previous Alarmists were stung by the recovery of the Antarctic, and the Coming Ice Age of the 1970’s based on the Arctic Sea Ice growth.

  41. This has all been said before, but I suppose it bears repeating:
    1. We’re dealing with operational data, so there is always the possibility of errors that need to be corrected.
    2. We’re keeping an eye on our data, but we don’t see any problems in our data quality at the moment. If we do discover an issue, we’ll let users know as soon as possible and correct the data.
    3. Keep in mind that the final couple of data points include some interpolation and should be assumed to be preliminary. These preliminary points get replaced with more final data and thus the apparent slope can change.
    4. Our sea ice maps are not an equal area projection. Thus one cannot compare extents by counting grid cells – this is probably the reason for the 7.5% vs. 3% discrepancy. Steve has been alerted to this issue in the past, but seems to have forgotten it.
    5. In comparing different products (e.g., JAXA, ROOS, DMI), it’s important to understand that there are many sources of differences, not simply the concentration threshold (30% vs. 15%): (1) sensor (JAXA uses AMSR-E; DMI uses multiple sensors), (2) type of sensor (DMI uses a combination of passive and active microwave sensors; the others use passive microwave), (3) algorithm (i.e., how the raw data gets converted into sea ice concentrations, and (4) ancillary information (e.g., land masks, quality-control parameters, etc.).
    If there is a large divergence between products, it’s an indication of a possible issue with one of the products. However, there can be normal divergence between products for one or more of the 4 reasons above, particularly during summer due to things like: (1) surface melt, (2) atmospheric effects, (3) type of ice, and possibly other factors. For example, for much of the year JAXA extents are lower than NSIDC’s, but towards the end of summer NSIDC begins to estimate less ice. The same generally happens with the ROOS product.
    These issue are typical in dealing with climate data. No measurement tool is perfect, all have uncertainties. Looking at multiple datasets can provide greater insight into physical processes, can illuminate errors, and when there is good overall agreement – as in the long-term decline in Arctic sea ice extent – high confidence in the results.
    Walt Meier
    NSIDC

  42. Günther Kirschbaum says:
    August 4, 2010 at 4:06 pm
    “If weather conditions turn into those 2007 experienced there is a very good chance of a new minimum extent record. And that after 5 weeks of weather conditions that are adverse to ice melting, with all those clouds, lower temperatures and the Beaufort Gyre and Transpolar Drift Stream stalling completely (reversing even).
    Despite those adverse conditions during the most important phase of the melting season, the ice looks in a terrible state and could reach a new record minimum extent, if weather conditions switch back again. Amazing, really.
    If the Arctic shows another ‘recovery’, it will be because very, very thin ice managed to get spread out enough and survive long enough for the cold air to come and let the sea water between the floes freeze up again.
    Come in, CryoSat-2. We need your data.”
    So in other words Gunther, regardless of the result Global warming is to blame. ROFL. I can picture us entering another ice age and Gunther will still be around trying to claim that AGW has somehow brought it about.
    All signs are that we are now heading into a strong La Nina event, something not seen for over a decade. Will this cause the same sort of step down in global temp anomalies (UAH satellite data) as the step up we saw following the 98 el-nino. If it does I seriously doubt you will see a continuing trend of reduced summer minimum extents in the Arctic.
    Little wonder the frantic efforts by AGW advocates to get their money making schemes in place before things start to cool and people realise what type of a scam is being run.

  43. There is a simple maxim: if you have to choose between explanations for something and one of them is conspiracy and the other is error, you should be choosing error every time. Conspiracy theory thinking is anti-reason.
    And in this case the error is being made by those who are claiming that there is a discrepancy. NSIDC and DMI measure two different things .

  44. James Sexton,
    You say that ‘even if they are measuring different things, the discrepancy should not be that great’. On what basis do you make that claim?
    As to the claims of other manipulation and adjustment – basically, claims of some vast conspiracy to acheive global dominance via the stealing of underpants – they are simply further examples of where conspiracy theory thinking leads one.
    Scrub conspiracy theory thinking from your minds, people. The world may make less sense to you initially. But your thinking will be the better for it. 🙂

  45. John F. Hultquist says:
    August 4, 2010 at 6:57 pm
    David Gould says: fraud? ~shakes head in wonder and despair~
    August 4, 2010 at 5:29 pm
    I have the same feeling. Many folks seem to think that someone is in charge. Who? Anyway, those calling fraud ought to spend a few days writing out a very detailed plan as to how they would accomplish what these agencies and their people are trying to do. Start with the equipment you will need. Then the people to do it. Then begin with what you would do tomorrow morning, and tomorrow afternoon. Keep repeating. Check back in a couple of weeks and let the rest of us know how you are doing.

    I expect/assume that the majority of working “climate scientists” are actually no more or less honest than other scientists or the public at large. I think that the practice/process of climate science has become corrupt. The governing assumptions are “theory” led, rather than “data” led. Interpretations of data that contravene the current theory are routinely ignored/discarded in favour of interpretations of data that validate the theory.
    In this way, issues with the theory are glossed over. The theory of AGW is not (to my mind) strictly incorrect – it is incomplete. Once you add in points such as “water vapour as a negative feedback” it becomes more complete.
    The trouble for the true believers is that the more complete forms of the theory eliminate the catastrophism and hence the political and financial utility of the theory – scary stuff if your personal beliefs and livelyhood depend on AGW. No wonder that people working in the field look the other way, or focus on the “little window” of their research that allows them to stay within the dogma.
    I’ts not fraud – just garden variety “don’t rock the boat”.
    Mind you, there are people within the AGW industry who actively work on non-scientific principles that can be summarised as the silencing of dissent, and the manipulation of data – and that amounts to fraud.

  46. Walt Meier says:
    August 4, 2010 at 8:31 pm
    ………and when there is good overall agreement – as in the long-term decline in Arctic sea ice extent – high confidence in the results.”
    Fair enough Walt, but questions are now being asked with regards the implications of whats happened since the 1997 record melt which took out a lot of multi-year ice.
    If you argue theres been no recovery, you can also argue that there is no evidence of a further decline to support the death spiral argument. If anything was going to sound the death knell for Arctic Ice, surely it should have been the 2007 melt along with what were being told are record temps in 2010.
    And yet here we are in August and every possible measuring indicator shows a greater extent than 2007, some showing considerable more ice than 2007. From an Artic Ice death spiral viewpoint this hardly fits.
    Incidentally there is every possiblity that the 2010 minimum extent (based on JAXA data) will be within a few hundred thousand sq km of the 2002 result.

  47. Walt
    Thanks for your response.
    As you know, in late summer when most of the ice is north of 75N, the pixels are reasonably close to equal area. Whatever is going on here is well beyond the variance which would be associated with pixel size variations. I do these comparisons all the time, and there is something different going on during the last week or so.

  48. Thanks for that very straight forward explaintion on possible difference in Arctic sea ice extent estimates.
    I do have a question/request, if you would be so kind.
    Is it possible to obtain the DAILY Arctic sea ice area/extent digital data for the 2008, 2009, and 2010 calendar years?
    And if so, who should I contact for a data request of this type, or conversely where on the WWW is this data located (website, FTP, etceteras).
    NOTE: I’m not interested in the gridded data, just the daily time series of single valued Arctic sea ice area/concentration.
    TIA

  49. “DMI and NSIDC measure two different things: one is 30 per cent and the other is 15 per cent.”
    Did one use 15 in 2007 and 30 in 2010, and the the reverse switch? That would pretty mush destroy comparability, but if they were consistent, I would think the definition of “extent” would fall out of the calculation.
    Shows you what I know.

  50. R. Gates says:
    August 4, 2010 at 4:30 pm
    Worry not Steve, 2010 is showing no great change from the general downtrend over the past few years. These little differences may be of interest if you’re looking a the variations of sea ice within a specific week, month, or season, but these little variations and differences are insignificant when talking about bigger picture of climate. 2010 falls right in line with the general downtrend in year-to-year Arctic sea ice that we’ve been seeing for several decades as well as the accelerated downtrend we started seeing in 2007. If this trend is going to reverse, as the AGW skeptics would like to contend, then I surely would like to know:
    1) By what physical known mechanism will this reversal take place (i.e. what natural cycle will be swinging back the other way) GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.
    2) What is the anticipated year that we will see this uptrend begin?
    3) Will this be a “spiral” up, or should we anticipate a bee-line back to 8 million sq. km. summer minimums?
    =====================================
    Burden of proof is on you there. Nice try to introduce a roan fish (red herring) but it will not work anymore.
    By what physical known mechanism will you ever be able to prove anything?
    You can’t. You know just enough to be somewhat effective, but not enough to make the grade
    I do appreciate though….how you finally (after months and months of self-congratualtory misinformation) have finally started using the term General Circulation Models….as opposed to Anthropogenic Global Warming Models….but I digress.
    All the cream rises to the surface…eventually. But that still does not explain why you still believe in your religion.
    Hey….I guess homo sapiens are steeped in mythology….sometimes irreparably so.
    Chris
    Norfolk, VA, USA

  51. stevengoddard says:
    August 4, 2010 at 5:21 pm
    R Gates,
    We have already seen a reversal from the southerly winds which caused the 2007 low. What else are you looking for?
    _______
    So your contention is that the entire last several decades of slowly declining summer Arctic sea ice, with an accleration of that decline beginning in 2007 is all related to “southerly winds”? And is it your contention also then that these winds are now going to blow from some other direction, and that will reverse the trend, and so all the GCM’s just have it wrong? I just want to understand the basis for the belief (so far not seen in the data) that the Arctic sea ice is about the show a “recovery spiral”? I would think then that we will start seeing some positive Arctic sea ice anomalies at some point, as the recovery takes hold.
    And one final question…since we are also seeing an increasingly well documented slow warming and melting of permafrost across the Arctic and subarctic regions, are these “southerly winds” also blowing deep underground to move the permafrost around and warm it?
    Of course, I don’t believe it was only “southerly winds” that has caused the decades long slow decline of Arctic sea ice, but a longer term slow rise in global temps, amplified in the Arctic. Changes in the winds are one of several effects from changes in temperatures in the troposphere, as for example, we see with the Arctic Dipole Anomaly.
    But one final question

  52. Looking at multiple datasets can provide greater insight into physical processes, can illuminate errors, and when there is good overall agreement – as in the long-term decline in Arctic sea ice extent – high confidence in the results.
    Walt Meier
    NSIDC
    ============================
    High confidence??? I’m sorry, but will using a term like “high confidence” get you the funding you need?
    You are one of the premier experts on this subject in the world….but you will resort to using this type of terminology?
    What “high confidence”?
    The high confidence that the sun is going to rise over the horizon tomorrow?
    The high confidence that the Arctic sea ice ebbs and flows….and may have been on an ebb??
    What are you trying to prove….or hide?
    I would support your funding if there was high or low confidence doesn’t matter in the forecast….because I believe in the researcher (you).
    What I can’t stand are the politics that provide the unnatural forcing…either direction.
    What “high confidence”? On a 30 year scale?
    Big ****ing deal.
    Chris
    Norfolk, VA, USA

  53. James Allison says:
    August 4, 2010 at 5:52 pm
    R. Gates says:
    August 4, 2010 at 4:30 pm
    I believe the onus is on you to prove your idea that the recently observed slow decline in Arctic ice is due to AGW or human produced CO2 or whatever you are want to call it these days. You also need to provide proof to viewers here why the observed slow increase in Antarctic ice is also due to AGW.
    Put up the proof or stop the tedious “caused by AGW” you continually post on this website
    _______________
    James, I don’t have any “onus on me” to prove anything. I did not make up the GCM’s that forcast the slow decline of Arctic sea ice due to AGW. Far smarter people than me get paid to do that. I provide plenty of links to scientific studies when I’m trying to make a specific point. The AGW hypothesis has forecast for quite some time the slow decline in sea ice with specific reasons why polar amplification of general global warming will be seen. The fact that this appears to be happening doesn’t prove that the AGW hypothesis is correct, as the causes could certainly be Steve’s “southerly winds”. But the other evidence (also predicted by AGW models) such as stratospheric cooling, ocean acidification, permafrost melt, etc. starts to lean strongly toward the AGW hypothesis likely being correct to some degree. I’ll leave it up to the Ph.D’s, such as Julienne and Walt to have the “onus on them” to discover linkages and the details of exactly how AGW will be changing the Arctic environment..
    Also, in regards to the Antarctic, again, we’ve discussed this so many times here on WUWT that it really gets tedious everytime someone (usually a skeptic) trys to point at its small year-to-year positive anomaly and expect that fact to somehow refute AGW. I suggest you google it and find all the links to the science for yourself, but I’ll throw out one for free:
    http://psc.apl.washington.edu/zhang/Pubs/Zhang_Antarctic_20-11-2515.pdf

  54. @R. Gates August 4, 2010 at 4:30 pm
    “GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.”
    I agree we could well have an ice free summer Arctic. Eventually.
    No doubt it has happened many times before and may well happen again. Not holding my breath it will be in my life time.
    And if the summer Arctic is ice free, that proves what, exactly?
    If the Arctic north of the Shetland Islands was frozen solid one future winter, would you accept that the whole AGW hypothesis is nonsense? I doubt it, you’d be on here with some kind of weird explanation and be saying that actually, Arctic ice was only one tiny piece in a much bigger jigsaw. After all, the AGW hypothesis puts the bacon on most warmists’ table. Possibly yours too.
    What “multiple GCM’s have left out”? Well, there is skill and integrity, for a start.

  55. R Gates asks:
    1) By what physical known mechanism will this reversal take place (i.e. what natural cycle will be swinging back the other way) GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.
    2) What is the anticipated year that we will see this uptrend begin?
    3) Will this be a “spiral” up, or should we anticipate a bee-line back to 8 million sq. km. summer minimums?
    1) Cyclic natural cooling will take care of the cyclic natural warming quite nicely, it goes like this.
    The planet warms and the planet cools, the poles shrink and poles grow, ocean currents flow one way and then another and winds blow the ice one way and then another. In common sense land we like to call this the natural cyclic climate and its been happening for a very long time. So dont worry R Gates be happy and be assured that the ice will return soon, there will be no death spiral and the polar ice will not melt away.
    I dont know if you are aware of this but every GCM has been proven utterly wrong in the past so dont take what they proclaim seriously and remember models are not in any way shape or form reality. Models are not real, repeat this 50 times turn around and click your heels three times and you will be back in Kansas(reality) in no time.
    2) Its happening right now and has been for a while and believe it or not, as the planet cools the ice regenerates very quickly so by 2012/13 ice levels in the north will be as high or higher than 30yrs ago. No need to fret and worry be happy the poles are saved.
    3) Ice goes up and ice goes down this up and down is dictated by global temps and wind and ocean temperatures and currents, now remember R Gates, there is no need to panic and become despondent, what you are seeing is natural and has happened before, enjoy your life and be happy.

  56. John H.H.;
    1. Introduce “deliberate error”.
    2. Pay big bux for supporting evidence and obfuscatory publications and reports.
    3. Declare consensus.
    4. Prevent dissemination of data tending to falsify consensus.
    5. Use 3 to demand global taxes to continue and accelerate 2.
    Etc.

  57. A thanks to Walt Meier to his explanation at August 4, 2010 at 8:31 pm.
    I wish he had omitted “– as in the long-term decline in Arctic sea ice extent –” as this is a wholly unnecessary comment and unrelated to the excellent clarifications he set out to provide. If he had to comment on Arctic sea ice decline, perhaps it might have been wise to also say something about the Antarctic scene and the fact that sea ice extent around the two poles are roughtly in balance with the average. It is regrettable that these people always need to plug their AGW agenda, even in cases where it is not appropriate, and I would certainly prefer to have “neutral” scientists in charge of climate statistics. That would surely do away with all the conspiracy theories.

  58. When the real variable being measured has a high derivative, as it does now, it’s not surprising that different sampling techniques give different results.
    Why not show the discrepancies on past years to see if this issue is systematic to the measuring techniques?

  59. R. Gates says:
    August 4, 2010 at 10:27 pm
    I will back up R. Gates here that there really does seem to be a polar amplification effect whereby the poles warm or cool about 2 to 3 times more than the global average. This is not a climate model result, it just paleoclimate history.
    It should be outlined in more detail why this occurs however. Local Albedo effects are certainly the major part of the explanation however (how cold was the Arctic during the ice ages for example – 90% of the sunlight was just reflected off to space so there was no warming affect from the Sun at all during this period). GHGs might also have a bigger net effect at high latitudes is another. It could be also be that the Tropics do not change much at all (the Sun runs the show here) so global temperature changes are more a reflection of high latitude temperature changes than anything else (the math just means high latitudes need to increase/decline 2.5 for 1 to change the global average by 1).
    There is still lots and lots of ice at the poles however. There needs to be a major increase in temperatures, melting a lot of ice to result in any significant change in the current average global temperature. Some additional sea ice melt in the Arctic in August is just not going to do anything.

  60. mikelorrey: August 4, 2010 at 3:30 pm
    NSIDC counts meltwater pools on top of ice as open water, I’ll bet…DMI, on the other hand, only seems to have an agenda of measuring the ice, even if it is submerged under meltwater pools.
    Swell. Now in addition to new ice, multi-year ice, rotten ice, flippy-floppy ice, thick ice, and thin ice, now we’re going to have to distinguish between “wet ice” and “dry ice” (or “non-wet ice,” since we’re not concerned with frozen CO2)…

  61. R. Gates: August 4, 2010 at 10:01 pm
    And one final question…since we are also seeing an increasingly well documented slow warming and melting of permafrost across the Arctic and subarctic regions, are these “southerly winds” also blowing deep underground to move the permafrost around and warm it?
    Permafrost is frozen dirt — it doesn’t melt, it thaws, and the thaw doesn’t extend very far from the surface, so “deep underground” means about a meter or a meter-and-a-half.
    *Muskeg* melts, and it’s the reason anopheles mosquitoes can survive up beyond the Arctic Circle.

  62. For anyone trying to understand cycles I very much recommend Joe Bastardi’s video on sea ice. He clearly shows the connection the Pacific decadal oscillation, which as it has reverted you can see the ice coming back.
    I’m surprised the PDO has been dismissed by some people as not being the cause, when it is clearly in synch. with the ice recovery.
    This has been posited by Don Easterbrook, so I would suggest anyone who wants a scientific viewpoint to visit his website, i.e. that a delay before the recovery kicks in is to be expected. This does fit in with historical observations of the past.

  63. Dinostratus has a good suggestion as do EthicallyCivil (way up in beginning with 2nd posting) in explaining the divergence. Walt Meier comes across with valid points (as usual) as does John F. Hultquist with regards to the… “fun” theories.

  64. Hmmm….DMI’s site has gone back to showing Tuesday’s ice graphic. I saw Wednesday’s yesterday and would normally be looking at today’s at this time of the morning in the UK (0945 BST).
    WUWT?

  65. R. Gates says:
    August 4, 2010 at 4:30 pm
    1) By what physical known mechanism will this reversal take place (i.e. what natural cycle will be swinging back the other way) GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.
    2) What is the anticipated year that we will see this uptrend begin?
    3) Will this be a “spiral” up, or should we anticipate a bee-line back to 8 million sq. km. summer minimums?
    I’m having an attack of insomnia so I thought I’d give this a shot.
    1] Rigor and Wallace 2004 suggests that a prime influence in the decline in ice age and thickness in the Arctic was a paradigm shift in the state of the Beaufort Gyre and the TransPolar Drift that occurred at the end of the Eighties. This the commentary they included for the sea ice animation they included with the paper
    This animation of the age of sea ice shows:
    1.) A large Beaufort Gyre which covers most of the Arctic Ocean during the 1980s, and a transpolar drift stream shifted towards the Eurasian Arctic. Older, thicker sea ice (white ice) covers about 80% of the Arctic Ocean up to 1988. The date is shown in the upper left corner.
    2.) With the step to high-AO conditions in 1989, the Beaufort Gyre shrinks and is confined to the corner between Alaska and Canada. The Transpolar Drift Stream now sweeps across most of the Arctic Ocean, carrying most of the older, thicker sea ice out of the Arctic Ocean through Fram Strait (lower right). By 1990, only about 30% of the Arctic Ocean is covered by older thicker sea ice.
    3.) During the high-AO years that follow (1991 and on), this younger thinner sea ice is shown to recirculated back to the Alaskan coast where extensive open water has been observed during summer.
    The age of sea ice drifting towards the coast explains over 50% of the variance in summer sea ice extent (compared to less than 15% of the variance explained by the seasonal redistribution of sea ice, and advection of heat by summer winds).
    This is an updated version of that animation created by Rigor

    R&W suggest that recirculation of older sea ice from along the Canadian Archipelago, where it now ends up at summer minimum, back toward the Alaskan coast is a strong determinant factor in the continuing decline of ice age and thickness.
    If you watch the animation a few times, the drift pattern of the buoys illustrates how the smaller radius BG circulates the ice from along the coast and delivers it almost tangential to the TPD which is running in close alignment to the Prime Meridian. Once in the TPD the ice is expedited out through the Fram.
    Based on this information I would suggest that there will not be strong rebound in the summer minimum until the BG returns to a pattern close to what prevailed in the Eighties.
    From what I’ve seen the BG is not really well understood and there seem to be a number of factors suggested as influencing it with no clear winner, but most sharing the characteristic of not being controlled by or corollated with anthropogenic CO2.
    2]When then might we expect to see this change back to the old circulation pattern? Like most things in this argument that is a little hard to predict with any confidence, but I’ve been watching the sea ice drift maps at DMI for a couple of years and, to my eye at least, there seemed to some indications over the last freeze up that the BG was moving toward the larger radius state;
    http://ocean.dmi.dk/arctic/icedrift/index.uk.php
    Unfortunately they don’t monitor the ice drift through the melt season and those sites that do aren’t entirely comparable, so it will take some time to determine if that pattern shift is real and will be able to persist. Reports of the ice in the Eighties suggested that the old ice in the western Arctic was a decade or more in age, so even if the change is semi-permanent, it will take that long or probably much longer to get back to those conditions.
    In regard to the GCMs most models of the Arctic sea ice I’ve seen have indicated a long term decline, but almost none have been even remotely close to the observed
    data. As I have pointed out on a number of occasions, we tend to look with more fondness on errors that are in a directions that reinforce our own prejudices, but a model that misses big, even in a direction we like, is still wrong and not to be trusted.

  66. As you know, in late summer when most of the ice is north of 75N, the pixels are reasonably close to equal area.
    By my calculation a pixel at 75N will have cos(15°), which is 96.6 % of the size of one at 90°. So it ain’t that which is causing most of the discrepancy.
    BTW: every time I hear the “the AGW scientists are really smart” defence for a discrepancy, I tend to remind myself of the track record of really smart economists, such as the Nobel prizewinners at Long Term Capital Management. Which does not inspire confidence!

  67. Walt Meier says:
    August 4, 2010 at 8:31 pm
    “4. Our sea ice maps are not an equal area projection. Thus one cannot compare extents by counting grid cells – this is probably the reason for the 7.5% vs. 3% discrepancy. Steve has been alerted to this issue in the past, but seems to have forgotten it.”
    Well, not correcting for projection would have the opposite effect, would it not? It would tend to decrease the apparent disrepancy (very slightly), not increase it.

  68. Excerpt from: R. Gates on August 4, 2010 at 10:27 pm

    I did not make up the GCM’s that forcast the slow decline of Arctic sea ice due to AGW. Far smarter people than me get paid to do that.

    Far smarter people than you get paid to make up Global Climate Models that forecast the slow decline of Arctic sea ice due to Anthropogenic Global Warming.
    Then subsequently declines in Arctic sea ice get cited as evidence of Anthropogenic Global Warming, since obviously the model was correct as declines were noted.
    Meanwhile evidence that runs contrary to the models is routinely discounted and discredited as obviously in error since the models have shown themselves to be correct, namely a lack of statistically-significant warming, Arctic sea ice that is not continually declining every year, evidence showing previous declines in Arctic sea ice thus any current one is not unprecedented, etc, etc.
    And that’s not even getting into why a Global Climate Model would specifically have to consider any Global Warming to be Anthropogenic in origin to forecast a decline in Arctic sea ice.
    Obviously these people must be very smart indeed, since they are able to keep getting paid for making up this stuff…

  69. This is not so much a conspiracy theory as a bubble. Scientific funding appears to be proportional to the scale of the crisis predicted. Institutions inflate to fill the budget and then are no longer able to question the science. Scientists who do question it are unlikely to be viewed favourably by their employers – because the end result of them being correct is a cut in budget. A lot of the “science” you see on this stuff looks like it was written by a re-titled environmental activist. Cap and trade has made vested interests of banks (trading profits) and industrial groups that make a fat margin on this stuff. When was the last time you saw an environmental policy analysed on cost-effectiveness in the MSM? And this is supposed to be the most expensive problem mankind has ever faced.

  70. Bill Illis says
    …This is not a climate model result, it just paleoclimate history. It should be outlined in more detail why this occurs however. Local Albedo effects are certainly the major part of the explanation however (how cold was the Arctic during the ice ages for example – 90% of the sunlight was just reflected off to space so there was no warming affect from the Sun at all during this period). GHGs might also have a bigger net effect at high latitudes is another. It could be also be that the Tropics do not change much at all (the Sun runs the show here) so global temperature changes are more a reflection of high latitude temperature changes than anything else (the math just means high latitudes need to increase/decline 2.5 for 1 to change the global average by 1).
    The problem with this scenario is that there is no way it can end. Once the poles have been frozen and the CO2 has been absorbed by the cold oceans the two strongest warming effects according to AGW theory are at their minimum. So why, at this point, do we always get the fastest rate of temperature increase at any time in the paleo records? If Gates is right, there is no mechanism for recovery. The reality is that there must be a mechanism and it must be powerful enough to dwarf any greenhouse and albedo effect. The fact that no one knows what this mechanism is demonstrates how incomplete climate models are.

  71. David Gould says:
    August 4, 2010 at 8:40 pm
    “There is a simple maxim: if you have to choose between explanations for something and one of them is conspiracy and the other is error, you should be choosing error every time. Conspiracy theory thinking is anti-reason.”
    Your maxim is drivel. The supposedly rational “never infer malice over incompetence” notion is one widely promoted by the malicious – especially socialists, greens, authoritarian “liberals”, and other ideologues. It’s an effective propaganda cover for deliberate dishonesty. Sometimes the simplest explanation for something is that it’s a lie. If a burglar claims the door fell open when he brushed into it, he’s probably not telling the truth. If a second-hand car dealer tells you that the rust is nothing to worry about, he’s not being ignorant or incompetent; he’s trying to con you into buying the car at as inflated a price as he can get away with. If a politican or political spokesman tells you something that seems erroneous, he’s probably promulgating a porky; that’s his job. Even if it seems correct, the chances are high that you’re being subtly deceived. That’s how they get where they are – not by being stupid but by being good at lying. They can even lie to themselves, pretending that the “end justified the means”and that their selfish interests naturally align with the common good; they may even have “good intentions”, of the sort that pave the road to Hell. But they’re not thick. They’re scumbags, not idiots. Their errors are culpable errors.
    As for conspiracies, dishonest people engage in them all the time. Refusal to accept the existence of conspiracies is neither reasonable nor prudent. There are millions of conspiracies, some with similar goals, some with differing goals, some with rivalrous goals. Whenever two or more people cooperate in deceiving another, there is a conspiracy. It doesn’t take a secret society of Illuminati. Conspiracy is the ground state of mankind.

  72. toho
    You are correct. Pixels further from the pole represent larger areas in a polar projection, so any correction would increase the discrepancy. Walt has been alerted to this issue in the past, but seems to have forgotten it.

  73. I’ll throw out my cautionary remark once again. We hear from Gates, etc. that the Arctic melt is caused by AGW. But, it could very well be the other way around. As Dave Wendt pointed out above the extent may very well be related to the AO and other oscillations. If that is the driving force then we should see a warmer Arctic without any relationship to AGW. The warmer Arctic would slow down the transfer of heat from lower latitudes and could result in some overall warming of the planet.
    The point is we really don’t know what is the cause and what is the effect.

  74. Günther Kirschbaum says:
    August 4, 2010 at 3:56 pm
    “A chunk of old ice has broken away from the main pack and come to rest along the north coast of Alaska, east of Point Barrow, where it has begun to melt in the warm shallow shelf waters.”
    Hmmmmmm……makes me think…
    All we need is to stop sending out these ice-breakers filled up with AGW researchers , and all will be normal?

  75. David Gould says:
    August 4, 2010 at 8:40 pm
    And in this case the error is being made by those who are claiming that there is a discrepancy. NSIDC and DMI measure two different things .
    Arctic ice and Arctic ice?

  76. Some of you suggest we are looking at conspiracies, but in actuality I’m sure none of us really want a conspiracy when it comes to tracking and watching what the Arctic ice is doing. Besides noticing this discrepency that Steve finally brought to light in this post, because it became even more pronounced in this mornings NSIDC sea ice update. I’ve been waiting and hoping that igloo.atmos.uiuc.edu would get their sea ice comparison page up and working again. I have been using that page for over three years and it seems weird that soon after WUWT that put a link to that page on it’s new Sea Ice Monitering page it went down.
    I hate thinking it’s a way to keep us from easily comparing 2007 levels to what’s happening in 2010, but to me it’s a bit suspicious.

  77. 3%, 7.5%?
    Having Mark Surreze chosen to head this government agency is probably a good indication why algorithms are different. It appears to be a system wide problem.

  78. It appears to me that the DMI graph has not changed in about 60 hours. Is that correct?
    The DMI graph is about 44 pixels wide per month, and should move to the right by about 1.5 pixels per day. But zero pixel upgrades for over two days.
    ClimateSanity

  79. I was wondering what the narrative would be if Steve’s prediction of 5.5 million K^2 turned out to be wrong.
    The narrative appears to be taking shape: “I wasn’t wrong… the data is wrong!!!”
    I just didn’t Steve’s confidence in his prediction to melt so soon.

  80. RE David Gould: (August 4, 2010 at 8:40 pm) “There is a simple maxim: if you have to choose between explanations for something and one of them is conspiracy and the other is error, you should be choosing error every time.”
    This is all quite true, however we should always be aware that what constitutes error may be in the eye of the beholder. The action of a common world view on personal perception may give those who do not share that view the appearance of a conspiracy even if no such overt plot exists.

  81. Jeff P
    So far, my forecast has been too conservative.
    JAXA shows ice extent well above my prediction for the date. Odds are at this point that my 5.5 million forecast is too low.

  82. kadaka (KD Knoebel) says:
    August 5, 2010 at 3:10 am
    Excerpt from: R. Gates on August 4, 2010 at 10:27 pm
    I did not make up the GCM’s that forcast the slow decline of Arctic sea ice due to AGW. Far smarter people than me get paid to do that.
    Far smarter people than you get paid to make up Global Climate Models that forecast the slow decline of Arctic sea ice due to Anthropogenic Global Warming.
    Then subsequently declines in Arctic sea ice get cited as evidence of Anthropogenic Global Warming, since obviously the model was correct as declines were noted.
    Meanwhile evidence that runs contrary to the models…
    _______________
    Your point is made…but let’s stop right there for a moment. Show me the evidence that runs contrary to the GCM’s specifically about the slow decline in Arctic summer sea ice, leading to an ice free Arctic sometime this century. The Arctic sea ice has been showing a long term decline and permafrost is warming and melting in the arctic regions. The biggest deficit of the GCM’s is that they didn’t predict the acceleration in the melt that began a few years back, having obviously not accounted for some positive feedback. Some of this could be related to polar amplfiication effects, such as the increased frequency of the Arctic Dipole Anomaly.
    So in general, the GCM’s have pretty much got it right, and the science get’s better and more robust ocean-atmosphere linkages can be added to the models.
    But regardless of some posters doubts about it, I am a partial skeptic (when it comes to AGW). There certainly could be some other longer term natural cycle that “just so happens” to be coinciding with the general predicted effects of AGW in the Arctic. I very much welcome some scientific insight into what this other long-term cycle might be…currently, the 40% increase in CO2, to levels not seen in 400,000 years, seems to be the most simple and obvious explanation.

  83. stevengoddard says:
    August 5, 2010 at 7:06 am
    Jeff P
    So far, my forecast has been too conservative.
    JAXA shows ice extent well above my prediction for the date. Odds are at this point that my 5.5 million forecast is too low.
    ————
    Hmmm….current JAXA and NSIDC graphs show 2010 heading right toward that gap between the 2008 and 2007 lows…sort of exactly where I forecast we’d end up last March. You think the extent loss will only be 1 million sq. or less during the next 4-5 weeks of solid melt? Even with all the higher than normal water temps in the region? Interesting prediction…

  84. Steven
    could you remind us your prediction for the year minimum? Didn’t you state it would fall close to 2006 and be higher than the 3 previous years?

  85. R. Gates says:
    August 4, 2010 at 10:27 pm

    http://psc.apl.washington.edu/zhang/Pubs/Zhang_Antarctic_20-11-2515.pdf

    Thanks a ton for this link. To a skeptic who agrees with:
    1) the earth is getting warmer, and
    2) CO2 contributes,
    but not with:
    3) this is a problem that needs fixing,
    this paper is powerful. It assumes (correctly) 1, while making a mild argument against 3. It doesn’t project that there’s no problem — in fact, it notes major uncertainty — but it details a mechanism by which sea level isn’t skyrocketing now and may not later. Since sea level rise is one of the most prominent “catastrophic” effects of CAGW, this matters.

  86. from NSIDC ~ 75 percent down the Page, is OPEN about the Differences:
    [My] “Exec Summary”: AMSR-E / JAXA updated their algorithm so it is More accurate — but — AMSR-E comparisons with previous years are INVALID now ! Other than that, every method is just different –except in that ALL show a downward trend.
    — Note: I would caveat that HALF the “trend” is 2007. … MOST of their “trend” is a few UNUSUAL events.
    — (NSIDC = uses Passive MW with NASA mark I Algorithm)
    Quotes: … “Gloerson and Campbell (1991) estimate that ice concentration retrievals are accurate to within five to nine percent ” … ” Based on comparisons with analyses of synthetic aperture radar data, passive microwave overestimates open water by three to five times in winter (Kwok 2002). The winter coverage of open water is only about 0.3 percent.” [ie x5 reduces Ice area 1.2 percent = no big deal: real meat follows:]
    “A study based on digital versions of the U.S. National Ice Center’s (NIC) charts covering the Arctic every week from 1972-1994 (Partington et al. 2003), shows that NIC charts consistently report about four percent more ice per unit area than passive microwave retrievals from the NASA Team algorithm. This holds for November through May. Beginning in June, the difference rises to about 23 percent, and falls off gradually over the summer and into fall freeze-up. The difference after freeze-up, which begins in September over most of the Arctic, is probably due to the insensitivity of the passive microwave algorithm to thin ice. Both chart data and passive microwave data show a negative trend in integrated arctic-wide concentration over the period 1979-1994. The difference between the passive microwave and chart trends is statistically significant only in the summer, where it is about two percent per decade steeper in passive microwave data.
    A comparison of ice-covered area from the NASA Team algorithm with 18 years of Canadian Ice Service charts showed that passive microwave data markedly underestimate ice area by 30 to 40 percent during spring melt and fall freeze-up, for the Hudson Bay and East Coast regions. There is considerable scatter in the differences rather than a consistent pattern (Agnew and Howell 2002a) and (Agnew and Howell 2002b). The difference between chart and passive microwave-derived ice areas is greater for the Canadian charts than the U.S. charts. This is likely a reflection of the fact that the U.S. National Ice Center uses passive microwave when other data are not available, which is often the case for the central Arctic and other remote areas, while the Canadian Ice Service only rarely uses passive microwave data, relying instead on airborne and satellite radar, satellite optical, and visual observations for charts of the Canadian Arctic. These methods detect thin ice, lower concentrations of ice, and flooded ice much better than passive microwave data allows (personal communication, J. Falkingham, Chief of Operations, Canadian Ice Service, December 2002).
    Spot checks of the ice edge position using a 15 percent concentration cutoff against NIC ice charts show that when there is a broad, diffuse ice edge, the NRTSI and Standard Team products sometimes do not detect ice where the concentration can be as high as 60 percent. When the ice edge is more compact, the 15 percent concentration cutoff reflects its location fairly well. The large footprint of the 19 GHz channel means that a compact ice edge is smeared out in passive microwave imagery.
    A study comparing passive microwave sea ice concentration data with approximately 1 km resolution imagery from the Advanced Very High Resolution Radiometer (Meier 2005) focuses on the ice edge. Four SSM/I algorithms are used. The work illustrates how algorithms often underestimate concentration. The NASA Team underestimates concentration by about 10 percent on average, and by much more in some circumstances.
    Newer algorithms were developed that perform better than the NASA Team algorithm. An enhanced version of the NASA Team algorithm, NT2, incorporates the SSM/I 85 GHz channel and applies a forward-radiative transfer model to correct for weather effects that are exacerbated by use of the 85 GHz channel. This algorithm is the standard algorithm for arctic sea ice concentration retrievals with the AMSR-E instrument (Markus and Dokken 2002).
    We have considered using one of the newer algorithms for the Sea Ice Index, but this would require research and reprocessing in order to ensure that the record is consistent over the entire time series. The SMMR instrument did not include a high frequency channel like that used in newer SSM/I and AMSR-E sea ice algorithms.”
    PS: The Canadian sounds best – because, like PIOMAS, they add Every Ship & plane’s reports & pics. This produces long waits for updates.
    Can anyone find a Canadian data site ? I ran into their service’s site once, only got a weekly map — I’ll try to re-find it.
    PSS: THE best map for us is the ICE-AGE map http://nsidc.org/images/arcticseaicenews/20100804_Figure4.png
    Maslanik only produces about 1 a month though.
    or, again: http://iabp.apl.washington.edu/maps_daily_nsidcice.html
    …. note how the second, Bouy Map background shows a big area off Alaska of mixed Ice & water where there is a GAP in the Ice opposite Alaska in the first map. Also the Buoy map clearly shows the “bar” of thick ice crossing the Arctic Canada-to-Russia well “west” of the Pole — such as I talked about in the censored part of my July Sea Ice Outlook. Also seeable in TOPAZ http://topaz.nersc.no/topazVisual/matlab_static_image.php?action=NA_ARC_NWA_Function&file_prefix=ARC&match_date=20100803&depth=0005&variable_name=hice … wish I knew what “hice” was … try substituting 2009 : WOW — so different !! more ice by Volume is in that hugely thick area up against Canada & Greenland than in the whole 2010 map ! BUT the half of the Arctic (Russian side) where 2007,8, & 2009 lost most of their area – – it was like thin LACE then & is MUCH thicker this year.

  87. I wish I knew a way to make these a side by side comparison but I played on the JAXA site to get these images. The first one is from 8/4/2007:
    http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e
    And this one is from 8/4/2010:
    http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e
    And from what I can tell is that there is a lot more ice still in 2010 then there was in 2007. So I’m not sure how NSIDC is getting their graph which makes it look like the amount of ice is similiar to what it was in 2007.

  88. I hate to give an ego surge to R Gates by mentioning the name, but this is hardly the first time that arctic sea ice has had long periods of fluctuation. At least twice in the 20th century there was low arctic sea ice to the extent that the “northwest passage” was open – even for wooden ships. How have the GCM’s portray these transformations in the past? They haven’t and they can’t. They are stuck in extending a trend that experience has shown is quite variable and the models can’t portray these swings. They are imperfect to the extent that I continue to be amazed that anyone with any exposure to awareness of the periodic oscillation between glaciation and inter-glacial periods would give them any credence at all.

  89. R. Gates: August 5, 2010 at 7:12 am
    Show me the evidence that runs contrary to the GCM’s specifically about the slow decline in Arctic summer sea ice, leading to an ice free Arctic sometime this century.
    Show me the evidence that the Arctic is doing anything except what the Arctic has been doing for the past few million years — cooling, then warming, then cooling, then warming — and it was much warmer only tens of thousands of years ago.
    The Arctic sea ice has been showing a long term decline and permafrost is warming and melting in the arctic regions.
    Long-term? You mean since 1979? And permafrost thaws in the summer — that’s the reason the people up there can find mammoths that were frozen into it 45,000 years years ago (when it was warm enough for mammoths to survive through the winter, btw, because they *couldn’t survive there today).
    The biggest deficit of the GCM’s is that they didn’t predict the acceleration in the melt that began a few years back, having obviously not accounted for some positive feedback.
    It wasn’t a melt, and it wasn’t some imaginary feedback — it was a wind event which increased compaction coupled with the collapse of an ice bridge in the Framm which allowed more sea ice through the strait and into the Atlantic.
    So in general, the GCM’s have pretty much got it right, and the science get’s better and more robust ocean-atmosphere linkages can be added to the models.
    In general, the GCMs are models and it appears they’ve gotten it wrong, because they can’t replicate the observations.

  90. R. Gates
    And you also thought that the ice was tanking in June, based on the same methodology of extrapolating the graphs. My analysis considers a lot more variables, which is why I have been able to provide very precise predictions about trends and dates.

  91. stevengoddard says:
    August 5, 2010 at 4:15 am
    toho
    You are correct. Pixels further from the pole represent larger areas in a polar projection, so any correction would increase the discrepancy. Walt has been alerted to this issue in the past, but seems to have forgotten it.
    Quid pro quo…. Et tu Bruté? 😉
    When you have a mission, it is hard to look in the areas where you do not “find” supportive evidence. When you do find potentially divergent information, generally it is discounted as being an aberration or an artifact etc. Scientific research is always subject to human interpretation, especially in its formative stages.
    Being unbiased and impartial is not a human characteristic but can be cultivated with practice. This forum is the battleground, not for supremacy but for tolerance and understanding. There is no fraud but there is definitely conviction.

  92. Well, I said my next checkpoint was Aug. 5, and here we are. I think it’s reasonably clear my 6.0-6.2M prediction from late March will miss low. My bad for letting Anthony’s sage/seer/soothsayer taunting with an early prediction of his own taunt me into making a prediction that early. I won’t make that mistake again. Still waiting for minimum to make a full analysis. 5.5M or higher still lets me “beat the field” (median of the establishment-approved prognosticators).
    As I suggested three weeks ago, we’ve got a bunch-up at August 5th again, tho clearly 2010 is on the low side of it. But not enough to be overly worried about –just enough to take my original prediction out of the running.
    The next three weeks should be where the increase in 2nd/3rd year ice begins to make itself visibly felt in the extent trend and 2010 turns decisively (and positively) away from 2008.
    See you Sept 1.

  93. Sorry, more accurate to say my guess will have been high, not that it will “miss low”. I was being me-centric there and thinking of the extent missing my guess, instead of the other way around.

  94. stevengoddard says:
    August 5, 2010 at 8:38 am
    R. Gates
    And you also thought that the ice was tanking in June, based on the same methodology of extrapolating the graphs. My analysis considers a lot more variables, which is why I have been able to provide very precise predictions about trends and dates…
    ______
    Steve, the Arctic Sea ice WAS “tanking” in June, as it saw the largest decrease during the month ever.
    But really, let’s talk climate here, and stop talking about weather. When is your proposed seasonal recovery of Arctic Sea ice set to commence, and what will the mechanism for it? If it was all “southerly winds” that have caused this decline…when are these “southerly winds” set to reverse? Of course I disagree with this simplistic explanation, as I think these “southerly winds” are Arctic Dipole Anomaly related winds and have been increasing since around 2000, as the DA is becoming less of an anomaly and more a frequent player on the Arctic weather scene and as it becomes a more frequent event it moves from weather to climate.

  95. Reply to Dave Wendt
    August 5, 2010 at 2:36 am:
    Thanks for taking the time for such a thorough response. I’ve read much of this before, and it is at least one of the reasons that I’m still partially skeptical about AGW and it’s relationship to Arctic Sea ice loss. Though I’m not a scientist, my educated guess is that the dynamics of what is truly happening with the Arctic is more complicated than any models are able to currently forecast, and it’s not just one simple mechanism, like the gyre, or winds, or what have you, but a complicated relationship of physics, with feedbacks, both positive and negative, that aren’t well understood, and because we are dealing with a complex system existing at the edge of chaos, probably we’re not able to ever model.
    I’ve long said the next few years will be “make or break” for me, related to my general belief in the validity of the AGW hypothesis, and specifically I use the Arctic sea ice as my test case. If we don’t see a new summertime low Arctic extent by 2015 then I may pull back my belief to a 50/50 level from the 75/25 split I’m at now. Personally, with the solar max in 2013 and a likely new El Nino in 2012-2013, then there will certainly be enough global warmth to push down the summer extent, and I’m guessing we will and it will fall to around 2.5 million sq. km. in this time frame.

  96. R. Gates–
    Look at JAXA for Aug 5th-Sep 10 for 2008 vs 2009. What was the mechanism for the difference in results there when at the starting point (Aug 5th) there were practically identical?
    Same mechanism as will happen this year –increase in multi-year ice.

  97. I see NSIDC did their August update –they seem to be sitting on 5.0-5.27 as their prediction (not quite stated that way, but inferred, with wiggle room to be lower than that).

  98. stevengoddard says:
    August 5, 2010 at 10:26 am
    R Gates,
    Look for a significant increase in MYI in 2011.
    ———
    Steve,
    Why wait?
    How about a prediction of Arctic sea ice minimum for 2011 from you today.
    Since you assert that sea ice is recovering perhaps you’d like to put a marker at 6 million K^2. Or maybe 6.5?
    Surely if sea ice is recovering your prediction for next year should be higher than the 5.5 you predicted for this year.

  99. R. Gates says:
    August 4, 2010 at 10:27 pm
    James Allison says:
    August 4, 2010 at 5:52 pm
    R. Gates says:
    August 4, 2010 at 4:30 pm
    “I believe the onus is on you …
    [self snip]
    James, I don’t have any “onus on me” to prove anything…”
    I’m sorry to go back to this again in this thread but I cannot let it slide, Mr Gates. You claim that you do not need to prove anything because the GCMs tell you that arctic sea-ice will decrease (I paraphrase). This is conflation of science with the strange post-modern/post-normal “science” with which the climate debate is riddled.
    The GCMs are “THEORY”. They “predict” that arctic sea-ice will “decrease”. Well woopee-do. They have a 50% chance of being right. Now if they predicted the extent of sea-ice with error bars for next month/quarter/year then I think we could accept that GCMs model sea-ice reasonably well and they might have some value over some timeframe.
    The above interesting discussion on the minutiae of sea-ice measurement and comparison of data sets is very informative and is a discussion about OBSERVATION (EXPERIMENTAL OBSERVATION if you will). You cannot claim that you have nothing to prove in the discussion because your “theoretical” GUESS (with 50% probablity of being right) happens to be correct.
    Give us some numbers from the “theory”, for a reasonable period in the future, with error bars, then we will pay attention to GCMs. Until then, argue your case with science please not this post-modern/post-normal quackery which is doing untold damage to the climatological scientific reputation.

  100. RE: Jimbo says: (August 4, 2010 at 4:20 pm) “Joe Bastardi said around mid July 2010: ‘… The recovery of the northern ice caps will become more obvious in a two-steps-up, one-step-back fashion, but the Southern Hemisphere ice will retreat back to near normal. Overall global ice is right on top of normal and has had no change in the past 30 years. ‘”
    This sounds very much like we are only seeing the result of an annual competition between the Arctic and the Antarctic regions for a relatively fixed allotment of total global sea ice extent.

  101. R. Gates says:
    August 5, 2010 at 10:26 am
    Reply to Dave Wendt
    August 5, 2010 at 2:36 am:
    Thanks for taking the time for such a thorough response.
    You’re very welcome, and I mean that not just as the conventional response to an expression of gratitude. To me what has always made Anthony’s site an attractive place to spend time is the presence of a significant coterie of commenters who are are willing and able to articulate arguments that are against the grain of the majority. It’s a sad commentary on the present state of the discussion that WUWT is such a rarity in that regard. I respect the fact that, at the present state of our “knowledge”, there are many points of view that are least arguable, even AGW, though to my mind CAGW, not so much.
    You and those other commenters who are willing to come here and honestly advocate for your positions do us all a service by preventing the skeptical argument from degenerating to the levels of highly unfounded certitude that dominate on so many sites on both sides of this debate. To my mind no one in the this kerfuffle is completely “right” about what is occurring with our climate, myself in particular, and unless we are all willing to engage each other with honesty and mutual respect, the prospect of a “right” understanding of the climate arising is incredibly small.
    There are those among the denizens here who seem to have a negative attitude toward those argue for the AGW position, but for myself, I am appreciative and am grateful for your contributions. As Grandpa always said, “you can’t sharpen your knife on a stick of warm butter.”

  102. I invite anyone to download the sea ice concentration data and do their own calculations, using a 15% or 30% threshold. For the near-real-time data used in NSIDC’s ice extent graphs go here: ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/nasateam/near-real-time/north/
    you will also need to grab the pixel area per pixel file to do the extent calculations correctly since the data are not on an equal area grid (ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/tools/)
    Nothing has changed in the NSIDC data processing stream. Differences in ice extent between institutions has to do with differences in data sources (AMSR-E vs SSM/I), different algorithms (NASA team, Bootstrap, Bristol, AES-York, Bremen, etc.) and differences in threholds used for defining the ice edge). All algorithms that use passive microwave brightness temperatures for sea ice concentration retrieval will have problems once melt water is on the surface of the ice (the main reason to use extent rather than ice area). The important thing is to be consistent with the processing method and satellite instrument when doing time-series analysis.
    For more information on the sea ice processing done at NSIDC go here:
    http://nsidc.org/arcticseaicenews/faq.html#image_data

  103. stevengoddard says:
    August 5, 2010 at 11:17 am
    How could I forecast summer 2011, before seeing what happens in winter 2010-11?
    ————
    You already have with statements like ” Arctic sea ice is in recovery.” And there’s all the work you’ve done with PIPS models and data analysis to show that ice is in recovery.
    So I’d love to see you put some numbers on the table. Why stop with 2011?
    What do you see as minimum ice extents for 2011, 20012 and the infamous 2013.
    Some have said that the Arctic will be ice free in 2013, obviously they are idiots, but what do you predict for 2013?
    If you can’t do more than 6 months in advance you’re just doing weather, not climate.

  104. Jeff P
    Modelers consider climate forecasting to be in the range of “months to seasons.”
    No one can accurately forecast what ice conditions will be like in the spring, because it depends on the weather between now and then.

  105. Paul Birch ,
    Of course conspiracies exist. That is not what the maxim is about. The point is that conspiracy theory thinking is not a rational way of examining the world. Your starting point should always, without fail, be that there has been an error made by someone. If you can demonstrate that there has been no error made by anyone, only then should you move into looking for conspiracies. Further, even at this point you should look for the smallest possible conspiracy. If your conspiracy starts to contain dozens of people, that is strong – although of course not conclusive – evidence that there is no such conspiracy.
    As to leftists trying to convince everyone that conspiracies aren’t real, those of us on the left are, unfortunately, just as infected with anti-rational conspiracy thinking as those on the right – see 911 Truthers, for example.

  106. Amino Acids in Meteorites,
    The two measure differing concentrations of arctic ice, so they are almost bound to show different results.

  107. Spector,
    True – I term these ‘conspiracies of self-interest’. However, when such a conspiracy relies on fraud being independently committed – and that is what is being asserted by some people above – I think sceptism about the existence of such a conspiracy of self-interest is the most rational course.

  108. timheyes says:
    August 5, 2010 at 11:13 am
    “Give us some numbers from the “theory”, for a reasonable period in the future, with error bars, then we will pay attention to GCMs. Until then, argue your case with science please not this post-modern/post-normal quackery which is doing untold damage to the climatological scientific reputation.”
    ________
    This is the difference between what Steve does and what climate science is all about…which is essentially the weather vs climate issue. GCM’s are NOT MEANT to predict exact numbers because climate is about the longer term TRENDS, not how hot or cold it is right now or what the date in 2010 is that the shore fast sea ice broke away from Pt. Barrow.
    Here’s the point: GCM’s are about trends because climate is about trends.
    In this sense, climate is easier to predict than weather, because all it has to get right to be right is the trend, not the specifics, so long as it has the physical basis for forecasting those trends, which is of course the additional 40% CO2 that has been added to Earth’s atmosphere in the past few hundred years. Additionally, we’ve got consistent climate records going back hundreds of thousands of years, but of course no consistent weather data exists beyond a century or or two.
    The most recent and dramatic failure of GCM’s is not that they missed the general downward trend of Arctic Sea ice over the past many decades, which they got right, but that they failed to get the severity of the slope correct. So it was not one of direction but of degree. Certainly unaccounted for feedback issues are the reason, as will exist with a system existing on the edge of chaos.
    If somehow the Arctic sea ice reverses the downward trend over the next few years in some meaningful way (meaning heading back toward the 8 million sq. km. minimum), then I’ll reconsider my belief that the GCM’s are generally correct because a trend they have predicted (based on CO2 forcing) will not be happening.

  109. David Gould
    There are differences between :
    NSIDC and DMI
    NSIDC and JAXA
    NSIDC maps and NSIDC graphs.
    Blaming it on concentration thresholds isn’t going to fly.

  110. Julienne Stroeve says:
    August 5, 2010 at 3:05 pm
    ……
    Nothing has changed in the NSIDC data processing stream. Differences in ice extent between institutions has to do with differences in data sources (AMSR-E vs SSM/I), different algorithms (NASA team, Bootstrap, Bristol, AES-York, Bremen, etc.) and differences in threholds used for defining the ice edge). All algorithms that use passive microwave brightness temperatures for sea ice concentration retrieval will have problems once melt water is on the surface of the ice (the main reason to use extent rather than ice area). The important thing is to be consistent with the processing method and satellite instrument when doing time-series analysis.”
    I beg to differ Julienne. If the difference is in the incorrect measurement of melt water ponds on the surface as decreased ice and one model picks this up and records this as an anomaly and another model does not, then consistency in processing the data for a time series will not help.
    What NDISC is potentially showing is an increase in melt ponds at this time of year. I agree this is not necessarily a good sign but its not the same as saying ice has been lost altogether in an area compared to previous years which is the impression their chart provides.
    Incidentally, the JAXA number for 4/8 has been adjusted down by about 20,000 sq km making the second day in a row of downward adjustments. Given the averaging method they use this hints a slowdown in the melt. although I would prefer to see a few more days before drawing a conclusion.
    I’m still with Steven on the minimum being in the 5.5 million sq km range. Although, we would need to match the 2006 ice loss for the remainder of the season though to acheive this. Looking at the ice loss on an area by area basis and then factoring in drift from the buoy measurements and DMI temps, I do think this is a possibility.
    We need to watch the DMI temps very closely in the coming weeks. In 2006, the temps (north of 80N) dropped below zero quite early and you cant help but conclude this contributed to the slow late season melt in that year.
    If we see the temps drop below zero in the coming week on the DMI chart then perhaps we’ll see a JAXA minimum over 5.5 million sq km. Given the 5.25 million sq km result in 2009 I would have to say this would support a recovering ice pack.

  111. David W. says:
    “If we see the temps drop below zero in the coming week on the DMI chart then perhaps we’ll see a JAXA minimum over 5.5 million sq km. Given the 5.25 million sq km result in 2009 I would have to say this would support a recovering ice pack.”
    ____
    Really? Is that your definition of a recovering ice pack? It seems the bar has been set quite low for some reason. So anything less than 5.25 million sq. km. you would say shows no recovery, right?
    And BTW, the primary cause of melt right now is not air temps, but water temps, and they continue to run higher than normal throughout the Arctic from Greenland and the Barents Sea over to the Bering Sea, as they have for quite some time.
    ______
    Steve Goddard said:
    R. Gates,
    GCMs can’t model wind effectively – so there is no way that could have forecast the wind compaction which occurred in 2007.
    _____
    I agree with that to some extent, but I don’t agree with your underlying assumption that changes in wind patterns might not be related changes in other atmospheric and ocean circulation patterns that could have as their root cause AGW. I must go back here to our discussion of the Arctic Dipole Anomaly and the TREND of increasing frequency of the what might soon be called a “former” anomaly. You certainly are aware of research being done to link the frequency of DA to atmospheric pressure changes that could be the resulting of global warming? I believe even Julienne, who is far more versed in this sort of thing has discussed that here.

  112. stevengoddard,
    They do explain the differences between DMI and NSIDC. So we can cross that one off the list straight away.
    NSIDC and JAXA have *always* differed. They have different record minimums, for example. This is because they use different algorithms. So we can cross that one off the list.
    Apparent NSIDC internal differences have already been explained by Walt. Nothing unusual has happened. So we can cross that one off the list.

  113. And really, just one look at this graph:
    http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
    And this graph:
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg
    And this graph:
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
    And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???

  114. R Gates,
    Given that GCMs can’t model wind very well, you are going to have a very tough time making a case that the 2007 winds had anything to do with CO2.

  115. As an example of the differences between JAXA and NSIDC, these are the averages for April, May, June and July. The top line is NSIDC, the bottom line JAXA.
    14.69 13.1 10.87 8.39
    13.84 12.00 10.03 7.90
    The differences vary considerably, from .48 to 1.1. These are averages over the whole month, so daily differences are likely to show even greater variation.

  116. stevengoddard,
    If the sea ice map and the sea ice graph are generated from the same data, how can supposed discrepancies be real? Or are you saying that the two are created independently from separate data sets?

  117. Walt Meier says:
    August 4, 2010 at 8:31 pm
    To begin, a thank you for monitoring and addressing the earlier posts up to 8/4. Alot of information designed to accurately identify what is actually occurring with arctic ice has come out. Would you care to update your assessment?

  118. stevengoddard says:
    August 5, 2010 at 5:49 pm
    R Gates,
    Given that GCMs can’t model wind very well, you are going to have a very tough time making a case that the 2007 winds had anything to do with CO2.
    ________
    Fortunately (or perhaps unfortunately) it’s not my job to find the evidence that shows a link between the 40% rise in CO2 over the past few centuries and changes in wind patterns and atmospheric presssures in the Arctic. But undoubtedly at least a few dedicated researchers are looking at this very thing. GCM’s will only tell us that the pot will eventually boil (i.e. the Arctic will be ice free this century in the summertime), but they can’t tell us the exact path we’ll be taking to get their own what kind of feedbacks we’ll meet along the way…

  119. R. Gates says:
    August 5, 2010 at 4:38 pm
    “…Here’s the point: GCM’s are about trends because climate is about trends….”
    Reply: First off, I must applaud your tenacity. Given your statement above, would you say that the GCM’s are linearly trending or are they cyclically trending? A simple question, is it not? Because historical climate has been cyclical. Is it your belief that anthropogenic CO2 forcing is sufficent to disrupt the cyclical nature of climate? I await your well-reasoned response.
    Thank you,
    Ralph Dwyer

  120. R. Gates: August 5, 2010 at 5:43 pm
    And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???
    Well, let’s look at a *longer* term average.
    The Northwest Passage (NWP) has been icebound during the “modern instrumental period” and ships haven’t been able to transit without the aid of icebreakers, correct? If ships *could* transit the NWP without the aid of icebreakers, that would mean that the ice extent was well below average, correct? The historical record shows that ships transited the NWP without the aid of icebreakers at least twice in the mid-19th Century, and at least four times in the 20th Century, therefore, the ice extent was well below average during those periods, correct? Since ships have *not* been able to do that in recent years, then the ice extent must now be *above* the longer term average, correct?
    If you look at the “longer term average,” you’ll see that the ice extent is *never* average — it’s either above or below, and since we’ve only been getting pictures of the extent for thirty years, we can’t honestly claim we even know what the “longer term average” happens to be.

  121. stevengoddard says:
    August 5, 2010 at 3:48 pm
    No one can accurately forecast what ice conditions will be like in the spring, because it depends on the weather between now and then.
    ——-
    Steve,
    So you see each year as an independent event and are unable to make any assessment beyond 6 months in the future?
    In that case you shouldn’t be making grand pronouncements that sea ice is in recovery because you have no idea what is going to happen 6 months from now. In that one line above you have invalidated every forward looking statement you have ever made about ice extent.
    You are admitting here you have no clue what ice extent will be in 2011, 2012 or 2013 yet you continue to say that sea ice is in a long term recovery.
    Either you don’t know or you do but you can’t have it both ways.

  122. Bill Tuttle says:
    August 6, 2010 at 3:12 am
    R. Gates: August 5, 2010 at 5:43 pm
    And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???
    Well, let’s look at a *longer* term average.
    The Northwest Passage (NWP) has been icebound during the “modern instrumental period” and ships haven’t been able to transit without the aid of icebreakers, correct?

    During the last 3 summers the NWP has not been icebound and has been transited even by yachts and this summer will follow suit.
    If ships *could* transit the NWP without the aid of icebreakers, that would mean that the ice extent was well below average, correct?
    As it has been.
    The historical record shows that ships transited the NWP without the aid of icebreakers at least twice in the mid-19th Century,
    Not that I’m aware of.
    and at least four times in the 20th Century, therefore, the ice extent was well below average during those periods, correct?
    In a single season the first was the St Roche once in the 40s, and de Roos in 1977 when were the others?
    Since ships have *not* been able to do that in recent years, then the ice extent must now be *above* the longer term average, correct?
    But they have been for the last three years and shortly this year so your premise seems flawed.
    If you look at the “longer term average,” you’ll see that the ice extent is *never* average — it’s either above or below, and since we’ve only been getting pictures of the extent for thirty years, we can’t honestly claim we even know what the “longer term average” happens to be.

  123. Ralph Dwyer says:
    August 5, 2010 at 8:39 pm
    R. Gates says:
    August 5, 2010 at 4:38 pm
    “…Here’s the point: GCM’s are about trends because climate is about trends….”
    Reply: First off, I must applaud your tenacity. Given your statement above, would you say that the GCM’s are linearly trending or are they cyclically trending? A simple question, is it not? Because historical climate has been cyclical. Is it your belief that anthropogenic CO2 forcing is sufficent to disrupt the cyclical nature of climate? I await your well-reasoned response.
    Thank you,
    Ralph Dwyer
    _______
    First of all, yes, absolutely I believe the rapid increase (geologically speakinng) of CO2 is likely to be able to impact the cyclical nature of the climate to SOME extent. Certainly the Milanovitch cycles drive the climate in long term, but even longer than that are the geological cycles of CO2 and rock weathering. We know that during periods of high CO2, the hydrological cycle speeds up, weathering rock faster, which actually removes CO2 from the atmosphere, cooling the planet, slowing down the hydrological cycle, until slowly CO2 builds again, melting the ice sheets, and the cycle begins again.
    But a 40% increase in CO2 since the 1700’s is potentially a huge shock to a system, and the entire issue with CO2 is how sensitive the natural cycles are to such a rapid increase. GCM’s predict the TRENDS of AGW from this increase, which will be seen (and is being seen) in melting ice sheets, reduced Arctic sea ice, cooler stratospheric temps, ocean acidification, etc. If only one of these things were happening, then I be less the my 75% convinced that AGW is happening, but there seems to be too many indications that indeed the 40% increase in CO2 is having an effect. Though, as with any system on the edge of chaos, the exact path and feedbacks are not going to be predictable and we know know about them until they’ve started.

  124. Bill Tuttle says:
    August 6, 2010 at 3:12 am
    R. Gates: August 5, 2010 at 5:43 pm
    And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???
    Well, let’s look at a *longer* term average.
    The Northwest Passage (NWP) has been icebound during the “modern instrumental period” and ships haven’t been able to transit without the aid of icebreakers, correct? If ships *could* transit the NWP without the aid of icebreakers, that would mean that the ice extent was well below average, correct? The historical record shows that ships transited the NWP without the aid of icebreakers at least twice in the mid-19th Century, and at least four times in the 20th Century, therefore, the ice extent was well below average during those periods, correct? Since ships have *not* been able to do that in recent years, then the ice extent must now be *above* the longer term average, correct?
    If you look at the “longer term average,” you’ll see that the ice extent is *never* average — it’s either above or below, and since we’ve only been getting pictures of the extent for thirty years, we can’t honestly claim we even know what the “longer term average” happens to be.
    _______________
    We only have the data we have. Even a transit of the NWP does not tell us about the overall extent of Arctic sea ice, but only of the NWP. We know that the Arctic Sea ice has not had a positive anomaly since 2004 based on the 30+ year average of solid reliable data. Anything else beyond this is somewhat speculation, though sediments and other data can give us some idea of the longer term sea ice extent in specific areas.
    I favor the satellite data over any for a reliable record of sea ice. Next, I favor ice core samples over any other data for a reliable record of CO2.

  125. R. Gates: August 6, 2010 at 7:52 am
    I favor the satellite data over any for a reliable record of sea ice.
    Then you’re limiting the record to the period between 1979 and today. The ice is cyclical, and the cycle may be quite a bit longer than 31 years.
    Next, I favor ice core samples over any other data for a reliable record of CO2.
    I like ice core samples, too — “During deglaciation the two [temperature and CO2 levels] varied simultaneously, but during times of cooling the CO2 changed after the temperature change, by up to 1000 years. This order of events is not what one would expect from the enhanced greenhouse effect.”
    http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/icecore.html

  126. (Mods: we’ve gone somewhat OT, but I think the discussion is valuable.)
    R. Gates says:
    August 6, 2010 at 7:45 am
    Reply: Thanks for your response. A few more questions if you don’t mind? Given Bill Tuttle’s timely link above (thanks Bill), and that humans were probably of little consequence, if any, for the first 155,000 years covered by the graph (Fig. 1),
    1) what do you think causes the past CO2 increases as stated in your comment?
    2) From the same graph it appears to me that an approx. 100ppm rise in CO2 (+/- 180ppm to =/- 280ppm) accompanies an approx. rise of 6 to 8 deg. C (twice in the graph) could we not anticipate a further 6 to 8 deg. C?
    And,
    3) given the graph in Fig. 2 which depicts the current rise in CO2, which is approaching a 100ppm increase (with the human contribution somewhat miniscule), what do you propose we do about it?
    I think we’d better adapt and learn to enjoy the benefits of increased CO2. How about you?

  127. Speaking of discrepancies, doesn’t anyone try to reconcile the various extent and area calculations, or are they all done by separate parties, each paying little attention to the others?
    Note: My assumptions are that 30% extent is calculated by adding up the total number of 25 km2 squares containing at least 30% ice cover, and similarly for 15% extent, and that area is a calculation adding up the figures for the actual ice cover in all squares containing at least 15% ice cover. If my assumptions are wrong, stop reading here, as the rest is probably nonsense.
    Anyway, here’s what I mean: Take the AMSR-E 15% extent figure at the maximum of 2010, which was approx 14.4 mil km2 at the end of March. Now compare that to two other figures (taken from the graphs on the Sea Ice page and approximated): The Danish (DMI) 30% extent at the maximum in March/April appears to be approx 11.7 mil km2, and the total sea ice area appears to be approx 13.7 mil km2 from the NORSEX graph.
    Do these make sense taken together? Let’s assume for the sake of argument that ALL of the 30% graph is actually 100%, so that would add its entire value of 11.7 mil km2 to the area calculation. (Obviously this is high, but assume it anyway) Now, the difference between the 30% graph and the 15% graph is 2.7 mil km2 (14.4-11.7). Assume that all of that difference is 29.999% concentration. (Again, obviously too high, but assume it anyway) If that 2.7 mil km2 is 30% (29.999%) concentrated, it would contribute just 800 mil km2 to area. Thus, adding the absolute maximum contribution from the 30% graph and the 15-to-30% portion of the 15% graph, we get a total sea area (maximum possible if the graphs are correct) of 11.7 + 0.8 = 12.5 mil km2.
    Yet, the sea area graph shows 13.7 mil km2, a figure 1.2 million higher than the maximum possible derived from using the two extent graphs.
    To make the numbers work, either the 15% extent would have to be raised by over 4 mil km2 (to add the missing 1.2 mil km2 to area), or the 30% extent would have to be raised by 1.7 mil km2 (to again add the missing 1.2, bearing in mind that the portion coming from the 15% extent would be reduced by 0.5). Alternatively, the sea area calculation could be lowered by the 1.2 mil km2 discrepancy, a discrepancy that is obviously larger than that, due to the assumptions made here. (Again these are all April 1, 2010 approximated numbers, not present day)
    Most likely it’s some combination of the three adjustments, but something doesn’t appear to add up and the adjustments required to bring things into balance seem quite large. Did I go wrong somewhere; if so, where?

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