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    Arctic Ice March 2011
    By Patrick Lockerby | March 2nd 2011 03:36 PM | 59 comments | Print | E-mail | Track Comments
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    Retired engineer, 60+ years young. Computer builder and programmer. Linguist specialising in language acquisition and computational linguistics....

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    Arctic Ice March 2011

    In April 2010 a late upward blip in Arctic sea ice extent led some bloggers to write about 'recovery'.  The blip was anomalous, hence there is no reason to expect a repetition this year.  On the contrary, it is likely that ice extent will not increase by any significant amount before the 2011 melt season gets fully under way - if it is not under way already.

    In my recent article Arctic Ice 2011 - Sail, Steam And Satellites I stated my expectation that NSIDC would report February ice extent as being the lowest in the satellite record.  The NSIDC has just released its February report and states: "Arctic sea ice extent for February 2011 tied with February 2005 as the lowest recorded in the satellite record."

    I recommend that my readers read the NSIDC February report before reading here further.

    A tip of the hat goes to Tony O'Brien for alerting me to the release of the NSIDC report.


    The current state of the ice and some predictions

    In this, my first first monthly report for 2011, I focus on ice loss paths and growth / melt mechanisms, and the significant dynamic differences between feedbacks due to ice extent and feedbacks due to volume.  I also explain the relevance of sea ice age.  I couple these ideas together and explain why I expect the central Arctic to be essentially ice-free by the end of this Arctic summer 2011.

    The major paths by which ice is flushed out of the Arctic Ocean are the Fram Strait and the Nares Strait.  I suggest that we may now add a third regular loss path: the North West Passage.

    The image below, taken from the March 02 2011 NASA MODIS Arctic Mosaic, shows the state of the ice in Baffin Bay and nearby regions.  From my historical researches, I would say that this is the sort of ice distribution that explorers in the 19th century might have considered fairly unremarkable - but at the end of July, not the beginning of March.


    Baffin Bay - March 02 2011


    Fram Strait

    The most consistent channel for export of old ice from the central Arctic has always been Fram Strait.  The rate of ice loss depends on many factors, one of which is the actual extent of consolidated ice.  Sheets of ice resembling ice shelves have usually blocked half or more of the width of Fram Strait from the Greenland side.  By winter last year there were few remnants of this old landfast ice, with open water from coast to coast.

    The multi-year shorefast ice loss of last year will likely continue in 2011.  Already, much of the east coast of Greenland which was ice-bound at this time last year is ice free.  Scoresby Sound in particular looks to be at a more advanced stage of melting now than it was in May-June of last year.


    Scoresby Sound March 01 2011 - MODIS terra

    The ice along the shore of Greenland serves to reduce the rate of export from Fram Strait.  With most of this ice gone, the average flow of ice through Fram Strait will most probably increase.


    Nares Strait

    Although an ice bridge has formed this winter it is structurally weak.  The visual images from MODIS show an apparently normal ice bridge.  However, the snow cover hides the weaknesses.


    Nares Strait - March 02 2011 - MODIS terra.

    Radar images reveal that the ice bridge is not made up of well-consolidated thick multi-year ice as would normally be the case. 


    ASAR image of Kane Basin

    The chunks of thick ice are frozen together only loosely by new ice, rather than strongly by means of compressive forces and regelation.  The Kane Basin is almost entirely covered in new ice, adding nothing to the strength of the ice bridge.

    I expect the ice bridge to break up between 2 to 4 weeks from now - earlier if there are any strong gales coming down the Strait.


    The North West Passage

    There is an ice bridge in the North West Passage, located approximately at the mid-point of the main passage.  It shows up clearly in the thermal image below.


    North West Passage - March 02 2011 - MODIS aqua LST

    The ice in the main North West Passage is made up of chunks of older ice flushed from the Arctic Ocean in summer 2010, since embedded in new ice.  The ice south of the ice bridge appears to be fairly new ice and quite fragmented.

    If the general trend towards earlier melting continues this year, I expect the main NWP to be
    open as a passage for ice export by mid June to end of June.


    The age of Arctic sea ice

    What [NSIDC] maps show is that the ice got younger, not melted. How does ice get younger?
    Steve Goddard
    How does a population get younger?  If some factor tends to kill off older people or there is a spurt in the birthrate then a population will get younger.

    The Arctic Ocean is populated by chunks of ice of various ages.  In general, ice will age during its multi-year journey around the Beaufort Gyre or through the Transpolar Drift - of which more is said below.  Ice which is exported into warmer waters where it melts has gone to the place where age cannot weary it, nor the years condemn.  If such export is of long duration and / or frequent occurrence, then the ice - as a population of bergs of various ages - will get younger.

    Although older ice tends to be thicker due to slabbing, bottom growth, frozen meltwater etc., the fact that a particular area of ice is old must not be taken as an assurance of thickness.  As each year passes, ice rejects more salt, a driver of the thermohaline circulation.  Old ice is almost pure freshwater ice.  Young ice is quite salty - too salty to be used to make drinking water.  However, if some part of an old floe melts away each summer, the floe will reduce in mass as it ages.  It is only when old ice remains in the central Arctic and is compacted into masses that the total mass of old ice remains constant or increases.

    When the Arctic sea ice had a fairly constant average annual extent over decadal timescales the export of old ice was matched by the formation of new ice.  Average ice age, extent and volume were all fairly constant.  Of recent decades, and particularly of recent years, the loss of old ice has not been matched by persisting new ice.  Certainly, most of the past winter's meager growth of sea ice will fail to last long enough to become second year ice.

    The major characteristic by which the age of a mass of ice may be determined is its salt content.  Not extent.  Not volume.


    Ice extent and volume

    If we consider ice in its extent, neglecting volume for the moment, we shall see that the advancing line of summer sun - or the retreat of darkness, which amounts to the same thing - exposes the sea ice to heat from the outer edge inward.  This means that we would expect the ice  to be more likely to melt at its edges since they are exposed to  accumulating heat longer than the center.  This is indeed pretty much the case.

    At this point I would like to refer my readers to what I call the Best Effect - the fact that midsummer insolation in the Arctic is greater than the contemporaneous insolation in the tropical-equatorial zone.

    The Arctic in summer would be something of a tropical sea, but for its ice cover.  The ice - for as long as it lasts - insulates the sea from the atmospheric heat by sacrificial melting.  It also helps keep the ocean cool due to the albedo effect.  The albedo effect is greatly enhanced by any snow cover on the ice - of which more later.


    Volume

    Let us now consider volume, neglecting extent for now.  Obviously, volume without extent is pure thickness, and that is what we are considering.

    As stated above, ice protects the sea from atmospheric heat by melting, and from solar heat through its albedo.  It is fairly obvious that the greater the thickness of ice, the longer it can persist in its local extent despite melting.

    In general, thicker ice is more likely to last into winter and add to its age than thinner ice.  Thicker ice is thus - again in general - more likely to become less salty and hence mechanically stronger.


    Snow cover

    Snow is much more reflective than ice.  Just as ice protects the ocean against warming by means of sacrificial melting and albedo, so snow in its turn protects the ice.  Thin ice which is awash will lose its snow cover sooner than thicker ice which is holding the snow well above the waves.

    Where warm water is causing bottom melt, thick ice will - fairly obviously - persist longer than thin ice.  For as long as the ice persists it will protect the snow from the warm water, thus helping maintain the local albedo.

    In addition, regional (land) snow cover will help keep the regional atmosphere cool - an effect which will help reduce sea ice loss.  Again, if the snow lies on ice - or permafrost - it will be insulated against bottom melting from geothermal heating, thus prolonging the albedo effect.

    Although regional snow cover has been quite extensive this past winter, satellite images of the Arctic reveal geographical features in the visible spectra.  I take this as an indication of thin snow cover which will melt rapidly in the summer sun.


    Ice mobility

    Consider how sea ice might grow, starting with an ice-free Arctic ocean.  As the zone of 24 hour darkness grows, so does the ice.  Ice growth may well be expected to be greatest where 24 hour darkness lasts longest, as heat is radiated into space.

    By the beginning of 24 hour sunlight the ice cap has grown into a lens shape: thickest in the center and thinnest at the edge.  The summer melt will have most effect where 24 hour sunlight lasts longest, so the heat input will be greatest at the thin edge and least at the thick center.

    If no other factors come into play, the ice may grow in volume over the course of years - with no limit to total mass other than ocean depth.  The Arctic Basin might well freeze solid.  However, if we factor in a transpolar drift and a Beaufort gyre, the picture changes.  The transpolar drift carries thin ice to the center of the mass and carries thick ice to the edge.  The gyre carries much thick ice towards the Canadian and Greenland coasts.

    The net effect of mobility is to prevent the possibility of the sea freezing all the way down.  For as long as the gyre and the drift continue they set an upper limit on ice volume.


    Factors leading to sea ice loss

    The volume of Arctic sea ice will remain fairly constant over the long term for as long as the heat gain during the long Arctic day and the mass loss due to mobility combine to offset the ice growth during the long Arctic night.

    Any constant or increasing factor which tends to retain heat during the winter or enhance it during the summer
    will cause a long-term trend of ice loss. 

    Any constant or increasing factor which tends to make the ice more mobile will cause a long-term trend of ice loss.

    Any constant or increasing factor which tends to warm the ocean and enhance bottom melting will cause a long-term trend of ice loss.

    The increase in greenhouse gases - most notably CO2 - has increased the blanketing effect of the atmosphere.  Predictably, this has enhanced the rate of summer melt on average and has reduced the rate of heat loss to space in winter.

    Additionally, the increase in open water area promotes mixing of the water layers, so that cold water layers can no longer be relied on to insulate the bottom of the ice from the warmer waters which exist at depth.  I covered one aspect of this, Ekman transport, in a previous article:

    I suggest that Ekman transport is sending surface water under the ice where it promotes bottom melting.  This would be yet another feedback mechanism.  It would accelerate ice loss through thinning, showing up as faster than expected thinning - i.e. volume loss - in the central pack.
    July 21st 2010
    Biotransport And Ocean Mixing
    Greatly fragmented ice allows waves to penetrate further into the pack and most likely carries the mixed (warm) water into the pack.  I have not included this mixing and penetration as a 'given', below, as the concept has not as yet been robustly proven.


    Summary and predictions

    As this article has become quite long I shall halt at this point and defer discussion of the Greenland glaciers to a follow-up.  I shall merely state here that I think that another substantial calving from the Petermann glacier is imminent.

    I made the following predictions
    January 16th 2010 in my article Global Cooling : Beyond Parochialism

    2010:
    Many hottest weather records are broken in northern hemisphere.
    Summer arctic ice at record low in extent.
    By September the Arctic Ocean is freely navigable by both the northern sea route and the north west passage.

    2011:
    Reduced ice cover affects sea temperatures, in turn affecting Arctic current flows and air movements. Thinner ice, instead of piling up as pressure ridges due to compression effects, cracks into sections due to tension and agitation effects.
    The Arctic is virtually ice-free by late summer: there is open water at the North Pole.
    The fact of being broadly correct in most of my predictions during 2010 does not mean that I will be proven correct this year in the above and the following predictions for 2011.  But I respectfully submit that my successes make my 2011 forecasts more worthy of serious scientific discussion.

    Given:
    the overall increase in Arctic and sub-Arctic air and sea temperatures,
    the great fragmentation of old ice last year,
    the great reduction in old ice volume,
    the trend of old ice to be pressed against the coasts of Greenland and the Canadian archipelago,
    the weakness of the ice bridge - and of sea ice generally - in Nares Strait,
    the strong possibility of an open NWP,

    I expect that a great deal of ice will be lost via Fram Strait, Nares Strait and the Canadian archipelago.  By September the bulk of sea ice will remain only in the area along the coasts of the Canadian archipelago and Greenland, with an extent of substantially less than 4 million km2
    . - perhaps less than 3 million km2.

    By September there will be virtually no ice left in the Arctic ocean older than 2 years.

    The ice which remains will be almost entirely 1st year ice.

    As soon as the feedbacks combine to accelerate ice loss, the final remaining summer sea ice will vanish very rapidly, so that the following winter will commence with no sea ice cover.  I expect this to happen by 2013.


    I now hand over to my readers for comment, discussion, etc.

    [edit] - update posted March 08 2011 - Arctic Ice March 2011 - Update #1
    ----------------------------------------------------------------------------------
    Image sources:

    http://nsidc.org/arcticseaicenews/

    http://rapidfire.sci.gsfc.nasa.gov/

    Further reading:

    Rainville et al. Observations of internal wave generation in the seasonally ice-free Arctic. Geophysical Research Letters, 2009; 36 (23): L23604 DOI: 10.1029/2009GL041291


    Comments

    Wow. A bold, and unsettling, forecast.

    I hope you are wrong, Patrick--though perhaps from a political point of view it would be better if you were right. We do need a "wake-up call" rather badly.

    Either way, I'll watch with more than interest.

    logicman
    Good to 'see' you again, Kevin.

    Yes, the world needs a wake-up call.  Can you 'arrange' one?

    What an entrance to the next melting season, I am really impressed, I agree with you that we are not that far away from the total collapse of arctic sea ice. But I am surprised you that frank about the situation, that is impressive.
    Regards Espen

    logicman
    Thanks, Espen.

    I look forward to your comments and observations as the season progresses.
    With all due respect, you are welcome. I will keep an eye on the situation and together with all the other watchers we will hopefully get the information out, that situation is serious, and not only a joke! Regards Espen

    During January, networks of cracks propagated across the Arctic Ice. Those cracks will have let allowed water vapor into the Arctic Atmosphere. Water vapor in atmosphere will have kept the upper surface of the sea ice warmer, allowing heat from mid-waters to warm the ice from below. Many areas that appear to have competent sea ice, have only floating slush. Competent sea ice can support a surface layer of snow, which is highly reflective. Floating slush carries a surface film of water, which absorbs broad spectrum of radiation, facilitating melt.

    More over, Arctic sea ice floats in a surface layer of low salinity water. Competent sea ice protects this layer from storm mixing. With low strength sea ice, storm mixing could raise the salinity of the surface layer, instantly dropping the ice formation temperature from near 0C to -1.8C, making it harder for the ice to reform.

    logicman
    Aaron: welcome to my blog and many thanks for this contribution.

    I agree with the general idea as another feedback, but citations will help me in formulating a more robust forecast of Arctic trends.   Do you have any links to articles or papers on these effects - your own, perhaps?
    Thanks for this Patrick. This more or less lines up with my own dreary, but unverified, view. I'm inclined to the view that weather effects might hold the 2011 melt season back from your prediction. But even so, if the 2012 projected super hot year comes along as expected, your ice-free result will only be deferred, maybe untill 2013 or 14.

    As I see it, the only thing that can save any larger quantity of ice, by any measure, area/extent/volume, is the undeniable fact that the constantly reducing ice could change weather patterns in never before seen ways - which just *might* put off the evil day (if it doesn't make melt speed up along its current path).

    logicman
    ... the constantly reducing ice could change weather patterns ...

    But it has, Adelady.

    The Arctic and sub-Arctic climate today is quite different to what it has been for many centuries.  We are witnessing climate change in the making.

    Thanks for your comment.  Please keep them coming.
    Early on you say
    "and explain why I expect the central Arctic to be essentially ice-free by the end of this Arctic summer 2011"
    which sounds like you are sticking with your Jan 16 2010 prediction of
    "The Arctic is virtually ice-free by late summer: there is open water at the North Pole."

    But the prediction now being made seems to be
    "By September the bulk of sea ice will remain only in the area along the coasts of the Canadian archipelago and Greenland, with an extent of substantially less than 4 million km2. - perhaps less than 3 million km2."

    Do you therefore consider that extent of 3 to 3.5 million km^2 to be essentially ice free? (My working definition of essentially ice free was 20% of 1979 to 2000 average extent which is only 1.4m Km^2. 10% pre 2000 average or 0.7m km^2 I would accept as 'Ice free'.)
    Or is this a slight backing off in your predictions. A little backing off would appear to me to be a sensible adjustment to your forecasts in view of your 2010 prediction for "Summer arctic ice at record low in extent" having failed to occur.

    OTOH if http://snipt.org/wkyg is reliable in reporting PIOMAS3 volumes for Sept 2009 and 2010 as 5694 and 3915. A similar reduction of 1779 would bring 2011 volume down to 2136 km^3 which is only 54.6% of the 2010 volume. Tthat could still leave extent at ~4m km^2 with the rest of the volume reduction in thickness rather than extent or area. However, it could be claimed this does not take account of the factors you listed above.

    logicman
    Note to my readers:  this comment is addressed in the comments thread below.
    http://seaice.alaska.edu/gi/observatories/barrow_webcam
    They have a web cam video of an ice shunt Feb 17-18 2011 at Barrow. Amazing how the ice goes from static to massive movement and back to static. Yes it is slow motion (1 frame/5 min) but still interesting.

    Had a look at Nevin's Arctic sea ice graphs (all on one page) and there it was.

    Interesting analysis Patrick. I learn every time I visit your blog.

    logicman
    I learn every time I visit your blog.

    And teach, Tony.  That is what I love about science - and science20.com - the exchange of information by which we all learn and all teach.  Thanks for the link.
    Patrick,
    I enjoy reading your analyses, glad you are back. After following NSIDC and The Cryosphere Today all winter, I must say I reached similar conclusions. I have, however, not seen and data from The Polar Science Center (PIOMAS) since December 31, 2010. Are they having a computer problem or are ice volumes running so low, they feel the need for extra verification before publishing?
    On 03/03/11 Crandles said "OTOH if http://snipt.org/wkyg is reliable in reporting PIOMAS3 volumes for Sept 2009 and 2010 as 5694 and 3915. A similar reduction of 1779 would bring 2011 volume down to 2136 km^3 which is only 54.6% of the 2010 volume."
    I believe it is important to point out that this amount of decline can only continue for 2 more end of melt seasons, further supporting what Patrick said. Even if we consider a decline of 5792km^3 for the past four years at an average decline of 1448km^3 per year, this amount of decline can barely continue at most 3 more years. After that no further declines are possible in end of melt season Arctic Ocean ice.

    logicman
    ... this amount of decline can barely continue at most 3 more years. After that no further declines are possible in end of melt season Arctic Ocean ice.

    Vaughn: that was my take on it.  I have been trying to discover any plausible mechanism which might cause the rate of decline to slow down.  Every feedback I examine leads me to believe that no single negative feedback has the power to overwhelm the many positive feedbacks which are - in my opinion - growing more positive.

    My method is to look at the Arctic as a system of materials, motions and energies etc. and try to determine what it is doing and will be doing.  What I see is an Arctic which is losing its sea ice cover faster than most models project.  I put this down to a degree of mutual positive feedback - the phenomenon whereby two or more positive feedbacks to a system can act as positive feedbacks to each other's amplitude.

    Many thanks for this, and for your many other thought-provoking contributions.
    Wow, Patrick - we really missed your posts over the winter, but it was worth the wait. Nice job of handling the different factors at play - but I notice sea surface temperature is not among them. It seems to me that the amount of heat being brought from the Caribbean into the Arctic via the Barents Sea had a lot to do with the NE Passage opening last year, and I would expect something similar last year.

    Crandles, for what its worth, I can vouch for the PIOMAS data you link to. I had performed a similar-but-different exercise to the author of that data file, and his results were very consistent (though not identical) with mine. And as Vaughn observes, its difficult to escape the conclusion that it will hit zero for September in only a few more years.

    And I think you misread Patrick - he talks about the central Arctic - which I take to mean the central region of the Arctic Basin (not the whole Arctic Basin). The area at and around the north pole. A million sq kms of ice jammed up against Greenland and the Canadian islands is not inconsistent with and ice-free central Arctic. Note that the North Pole is not the centre point of the Basin.

    "My working definition of essentially ice free was 20% of 1979 to 2000 average extent"
    If one considers "ice free" in terms of volume rather than extent we are very likely to reach a point below 20% of the long term average this year. The long term average volume at minimum is ~16500 km^3. 20% of that is 3300 km^3. Since we've been losing an average of 1000 km^3 for the last nine years, you'd have to like the odds of losing another six or seven hundred km^3 this year. That might cover 3 million sq km's, but most of it'll be a thin skin of slush, not pack ice.

    logicman
    The long term average volume at minimum is ~16500 km^3. 20% of that is 3300 km^3. Since we've been losing an average of 1000 km^3 for the last nine years, you'd have to like the odds of losing another six or seven hundred km^3 this year.

    Indeed, FrankD.  I've been looking at the long-term trend of ice loss and I'm trying to combine as many factors as possible in a descriptive model of what has been happening.  In my opinion, we are definitely witnessing permanent climate change rather than annual or decadal weather variations in the far North.

    it'll be a thin skin of slush, not pack ice.

    At the end of summer, maybe.  However, I expect that even after the first few summers of total sea ice loss the end of winter would see a substantial amount of ice of 1 to 2 meter thickness.  But after the extent of end-of-summer ice hits zero, the extent of end-of-winter ice will decline rapidly to zero due to general regional warming effects.
    A very interesting post, with many bold predictions, including for the very near future (e.g. on Nares). I'm not so bold, although I find the summer volume numbers startling. I know we can rely on you to revisit and assess these predictions later in the season.

    logicman
    I know we can rely on you to revisit and assess these predictions later in the season.

    I shall certainly strive to do my best, Nick.  :)
    "The Arctic is virtually ice-free by late summer: there is open water at the North Pole."

    This is a somewhat aggressive prediction for 2011. It could very well happen, but even commonplace weather variations could also prevent it. That said, it seems virtually certain to happen some time in the next three years. Moreover, the trends would seem to indicate that by 2020 the Arctic will typically look like this not just at the September minimum, but from mid-July through early November. That much open water at the pole for that long a period will introduce completely new dynamics that can't be predicted from existing trends. Essentially, we are rapidly approaching a point at which the factors determining Arctic (and indeed, Northern hemisphere) weather for the past 100,000+ years will be significantly altered... and we really don't have a clear understanding of what the results of that change will be.

    logicman
    ... we are rapidly approaching a point at which the factors determining Arctic (and indeed, Northern hemisphere) weather for the past 100,000+ years will be significantly altered... and we really don't have a clear understanding of what the results of that change will be.

    All the more reason to invest time and money in more climate / Arctic research, I would say.  Not that any politicians are likely to heed my advice.

    Many thanks, CBDunkerson, for your input to these discussions.  Please keep 'em coming.  :)
    FrankD, Thank you yes I did miss the 'central' so appologies to Patrik for that. However my version of 'central' is as per CT it does reach Greenland and Canadian Archipelago making the central region the last refuge of the ice. Archipelago has area under 0.2m km^2 in Sept. Even if that doesn't reduce, I don't see how you can get down to ~1.4m km^2 in central region while having circa 3m km^2 in Northern hemisphere so I still need to either adjust my understanding of what is meant by essentially ice free or be left with a discrepancy in Patricks predictions.

    I get the impression that essential ice free is seen as too aggressive a prediction while predictions around Maslowski's 2016 are gaining more support and William Connolley's still have summer sea ice in 2050 is losing support. I don't claim to have a comprehensive analysis of all the predictions.

    http://farm6.static.flickr.com/5132/5496221941_c96157b761_z.jpg

    logicman
    Crandles: your apology is not needed.  I thank you for pointing out the ambiguities in my article.  I shall prepare a chart for my next update to clarify the prediction.

    If the Nares and NWP export a large amount of ice this year 2011 then by the time winter comes there will be a lot of (2010) broken ice in those passages and in Baffin Bay.  If the end-of-season ice lies mostly in Baffin Bay, Nares and NWP, together with ice pressed against northern coasts, and adds up to even 4 million km2, I think it would be fair to say that the central Arctic Ocean - i.e. the location of the Beaufort Gyre and the present location of the transpolar drift - will be essentially ice free.

    Never forget that the many charts and graphs of extent cut off at from 15 to 30 percent ice.  That is from 70 to 85 percent open water - readily navigable by a stout ship.  Would you agree that an Arctic ice cap which resembles the summer marginal ice zone of former decades might be fairly categorized as 'essentially ice free'?

    I welcome all intelligent comments, favorable or no.  Please continue to keep me on my toes - even if I have to buy orthopedic shoes. (Ballet shoes are definitely out of the question!)  ;-)
    Crandles, thanks for posting the following link: http://snipt.org/wkyg I did a little number crunching on this data that may be of some interest:

    1. From about 1979 to 1990 Arctic Ocean ice melt ranged from about 13,500km^3 to about 15,000km^3 per year. Each year about 44% to about 51% of the ice melted.
    2.From 1991 to 2006 ice melt each year ranged from about 13,000km^3 to About 15,500km^3...very similar to 1979 to 1990. Each year about 46% to about 60% of the ice melted. From 2002 to 2006 58% to about 60% of the ice melted each year...a fairly substantial percentage increase.
    3. From 2007 to 2010 things started changing much more dramatically. Ice volume melted ranged from 16,150km^3 to 17,249km^3 in 2010...a substantial increase. Percentage of ice melted was about 73% to 74% in 2006-2009 and about 82% in 2010, quite a change from 44-51% melted each year in the 1980s.

    It also appears that the ice volume melt is increasing even with lower ice volumes. I have read arguments on the blog that claim the ice melt rate will slow when ice volume gets low. According to these numbers ice melt rate is increasing. I think we will continue to see melt rates increase right up to the very end similar to the way ice melt rates increase on a lake right up to the very end of the ice.

    Based on percentage factor, it would not surprise me to see a 90% melt off this year and virtually 100% next year unless we have a large volcanic eruption or worse. Since 17,249km^3 of ice melted last year it would seem reasonably prudent to expect that much or more to melt this year based on current trends. Once PIOMAS publishes maximum ice volume for 2011 we can subtract 17,249km^3 from that figure and get a pretty good idea of what minimum ice volume will be this year.

    I did not crunch any numbers on ice freeze up in case somebody wants to do that.

    >"I did not crunch any numbers on ice freeze up in case somebody wants to do that."

    If you prefer it visually:

    http://farm6.static.flickr.com/5093/5499553902_593f3396a2_z.jpg

    I do expect the trend in the volume freezing each year to curl upwards much more as the volume declines - The negative feedback of less ice insulation is frequently mentioned in papers.

    The trend in the melt has a steeper slope and I suspect this indicates that the positive feedbacks like albedo effects outweigh the negative feedbacks like ice insulation. If this is the case, then there seems little reason to think that this won't continue to be the case and the trend in the melt figures seems likely to curl up more than the upward curl in the volume freezing.

    >"I did not crunch any numbers on ice freeze up in case somebody wants to do that."

    If you prefer a table of numbers:
    Year Max Min Freeze Melt
    1979 33540 18000 N/A 15540
    1980 32693 17960 14693 14733
    1981 31242 15412 13282 15830
    1982 30213 15582 14801 14631
    1983 30914 16574 15332 14340
    1984 31060 15810 14486 15250
    1985 31422 15951 15612 15471
    1986 31341 17632 15390 13709
    1987 32457 17402 14825 15055
    1988 32229 17089 14827 15140
    1989 31190 15622 14101 15568
    1990 29926 14586 14304 15340
    1991 30746 14601 16160 16145
    1992 29823 15980 15222 13843
    1993 30117 13570 14137 16547
    1994 29515 13808 15945 15707
    1995 27177 11586 13369 15591
    1996 27239 14352 15653 12887
    1997 28667 13679 14315 14988
    1998 29567 12833 15888 16734
    1999 28828 12484 15995 16344
    2000 27651 12369 15167 15282
    2001 27509 13103 15140 14406
    2002 27325 11415 14222 15910
    2003 26339 10692 14924 15647
    2004 25167 10196 14475 14971
    2005 25095 9998 14899 15097
    2006 24543 9707 14545 14836
    2007 22731 6072 13024 16659
    2008 23032 6256 16960 16776
    2009 21844 5694 15588 16150
    2010 21161 3915 15467 17246
    (N/A means the usual between not available, not applicable or the more likely not attempted.)

    <"The trend in the melt has a steeper slope and I suspect this indicates that the positive feedbacks like albedo effects outweigh the negative feedbacks like ice insulation. If this is the case, then there seems little reason to think that this won't continue to be the case and the trend in the melt figures seems likely to curl up more than the upward curl in the volume freezing."

    May I retract that to replace with:
    The trend in the melt has a steeper slope and I suspect this indicates that the positive feedbacks like albedo effects outweigh the negative feedbacks like ice insulation. If albedo and ice insulation were the only feedbacks or at least clearly dominant over other feedbacks, then there would seem little reason to think that the same relationship won't continue to be the case and the trend in the melt figures seems likely to curl up more than the upward curl in the volume freezing. If there are other feedbacks that can approach the importance of albedo and ice insulation then the situation becomes less clear. I have no idea whether snow cover or other feedbacks could approach the importance needed and I am rather unclear about what I would epect from snow cover. Less ice cover means more potential for evaporation and more precipitation as snow but does this generate more snow depth or is the ice so much thinner that it cannot support as much snow. Also does the snow have more effect on albedo or on insulation? Are there sufficient competing effect to be able to rule it out an an important feedback? I just don't know.

    If you prefer the melt freeze data in a table.
    Year Max Min Freeze Melt
    1979 33540 18000 N/A 15540
    1980 32693 17960 14693 14733
    1981 31242 15412 13282 15830
    1982 30213 15582 14801 14631
    1983 30914 16574 15332 14340
    1984 31060 15810 14486 15250
    1985 31422 15951 15612 15471
    1986 31341 17632 15390 13709
    1987 32457 17402 14825 15055
    1988 32229 17089 14827 15140
    1989 31190 15622 14101 15568
    1990 29926 14586 14304 15340
    1991 30746 14601 16160 16145
    1992 29823 15980 15222 13843
    1993 30117 13570 14137 16547
    1994 29515 13808 15945 15707
    1995 27177 11586 13369 15591
    1996 27239 14352 15653 12887
    1997 28667 13679 14315 14988
    1998 29567 12833 15888 16734
    1999 28828 12484 15995 16344
    2000 27651 12369 15167 15282
    2001 27509 13103 15140 14406
    2002 27325 11415 14222 15910
    2003 26339 10692 14924 15647
    2004 25167 10196 14475 14971
    2005 25095 9998 14899 15097
    2006 24543 9707 14545 14836
    2007 22731 6072 13024 16659
    2008 23032 6256 16960 16776
    2009 21844 5694 15588 16150
    2010 21161 3915 15467 17246

    Hello. I think there is still some space for hope. One model in particular the PIPS should be looked at. The PIPS isn't observational data, rather it is a prediction based on other parameters, nevertheless it has reasonable or good accuracy. (Source: http://www7320.nrlssc.navy.mil/pips2/archive/retrievepic.html?filetype=T...).

    The reason I am hopeful is that the ice over the arctic basin does appear to be thicker than this time last year, which could be put down to a less strong NAO. Personally I predict the Arctic ice will have a much larger extent this year and last year, I expect similar to 2006.

    I think you are being too aggressive , in three ways. First, according to http://saf.met.no/p/ice/nh/type/imgs/OSI_HL_SAF_201103041200_pal.jpg , the amount of second-year and older ice in the Arctic is comparable to the same time in 2009, and even if Nares Strait loses twice as much ice as in 2007 that is still only enough to deplete the second-year and older pack by maybe 20% in the upcoming months. Second, the surface waves, even in completely open ocean, are not capable of significantly stirring water up at depths greater than half their wavelength, simply because the mechanical displacement amplitude of water falls off exponentially going down from the surface as exp(-depth*2pi/lamdba), where lambda is the wavelength of the surface waves. http://en.wikipedia.org/wiki/Wind_wave Given the halocline depth of 150 m at http://en.wikipedia.org/wiki/Halocline , you cannot validly argue for the "warm water bottom melting effect" you described unless you postulate large wind-driven waves of wavelength greater than 300 m (1000 ft.) . And this would only happen in ferocious tropical storms and tsunamis.
    Third, you are over-estimating the magnitude of the ice-albedo effect. The snow is normally gone over the Arctic in the first week of June, leaving an ice albedo of 50% in the visible for a sun angle of 33 degrees - noon near the summer solstice at 80 degrees north. In the near infrared (Half of sunlight is infrared!) is it significantly lower than 50% because of some vibrational overtone absorption (Which water and ice are good at due to their polar bonds with H-atoms). The difference between the 1979-2000 average and recent years within the true Arctic Ocean is confined mostly to August and September as far as open water in the Arctic Basin proper is concerned, and by then the insolation is much lower than in June. So because of those two reasons I think you are exaggerting the ice-albedo effect.

    But none of this is to say we don't have a serious climate problem. The anomalous, unseasonable melting of the ice in the sounds of Greenland is, in my opinion, deeply concerning due to its potential to de-stabilize Greenland's glaciers, leading indirectly to a potential mechanical de-stabilization of Greenland's ice sheet, leading ultimately, if it is extreme enough on business as usual, to catastrophic sea level rise this century. We know there is a real problem here, but as far as Arctic sea ice goes I think you are being a bit too extreme.

    logicman
    Anonymous: many thanks for your comment and the points you raise.

    I need to cover ocean mixing in more depth - pun intended.  My reference to bottom melting should not be taken as referring to ocean bottom water, btw, in case anyone is confused about that.  If warm surface water is advected into and under broken ice it will promote ice-bottom melting.

    As to the altitude of the sun at various latitudes:  you are correct to specify noon altitude - many writers fail to note this.  But noon is an abstraction of a moment in time having no duration, so any calculation of albedo referred to a noon base will generate a static model: a snapshot. 

    In the 24 hour day regions, the altitude of the sun varies during the day.  Any particular mass of ice will be warmed directly by the sun - and will reflect sunlight/heat - at continuously varying angles.  It will also be warmed continually by re-radiation and by atmospheric contact.  Again, I need to cover this in some depth.

    Please come back and check for further articles and updates.  I particularly welcome comments which remind me of factors which I need to address - or address in more depth - in my articles.

    Thank you again.
    Thanks for the discussion about ice volume. My main intent was to use beginning of the melt seasons' ice volume and determine the percentage of that that melted each season and use that as another predictor of future ice volume. Those numbers along with freeze up numbers should also represent the combined effects of feedbacks to this point. When we go from 50% of Arctic Sea ice volume melting each year in the 1980s to 70% to over 80% melting each year for the past few years that looks to me to like a clearly significant trend without doing further statistical analysis on it.
    If the rules do not change then it looks like in 2 to 3 years the ice will be pretty well gone at the end of summer melt. If the rules do change, however, this will most likely not be true.
    So the big questions are, "How will the rules change and how much will they change?" Obviously, there are three different possibilities with a wide range at the ends. The changing rules will cause the ice to disappear faster than now, cause little future change in current melt rate, or cause it to not melt as fast. Currently, I am leaning towards the first two possibilities although there is copious discussion about all three possibilities.

    I believe the weather situation, especially in northern Europe (The Nordic Countries), already shows there is a major change, the last 2 winters have been far colder than the average 10 years, and it is believed the reason is, that due to "hot" weather in the arctic the cold air is pressed down south towards the Scandinavian Peninsula, what that means in the future is a big? At least to me!

    The fact that Greenland sea ice area has been almost constantly negative recently tells me arctic is losing ice even in winter, for it's the main channel for ice export that only occasionally stops, unlike Nares or NWP. The flow in the Bering side is mainly TO the arctic so that's a reason for early melt there in recent years. In 2007 ice just barely held together between Siberian islands and Greenland.

    logicman
    Thanks for the comment, jyyh.

    I raise the point in my article - or try to - that export of sea ice into the Greenland sea via Fram Strait is greater of recent years than in historical times.

    You are quite correct that the Fram Strait is the main channel for ice export.  It always has been.  My contention is that if - as I expect - the Nares Strait and the multiple channels through the Canadian archipelago become regular ice export channels then ice loss by advection will increase dramatically - a positive feedback to sea ice volume loss.
    Nevin has done an analysis of Arctic ice volumes using Topaz data. If anything the loss of winter ice volume is even scarier than the loss of summer ice. As you showed with the George Best post, an enormous amount of heat is used up melting the ice each summer, what will happen when there is no ice to melt and the open sea absorbs rather than reflecting heat.

    Hello Patrick

    As you reported earlier, Peterson will probably calve again this year, the crack about 10-12 km behind from the front of the glacier is now about 80% across as you can see on this image from March 5 :
    http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/201103050003.ASAR.jpg

    If that piece get off it will be about +/- 170km2 or in more popular terms, twice the size of Manhattan.
    Regards Espen

    logicman
    Espen: I've been watching the ASAR images as they are posted. In my view, the fissure now extends completely across.  Other fissures seem to be growing behind the prominent one.  It appears to me that we shall see this great ice island calve, and then see two more of comparable size before the decade is out.  I shall be posting graphics soon showing where the fissures appear to be.
    Hello Patrick (again) just puzzled about that massive piece of rock to the left (south) of Petermann and north of Humboldt, will it become an island eventfully? And what will be its name?
    Regards Espen

    logicman
    what will be its name?

    Espeniola ?  ;-)
    PIOMAS http://psc.apl.washington.edu/ArcticSeaiceVolume/IceVolume.php just published the Arctic Ice volume as of February 28, 2011. From the looks of the graph it appears that the Arctic has just a little more than 1000km^3 less of ice than at this time last year...as best I can tell. If we have a melt similar to 2010 this will bring the ice volume down to under 2000km^3 by the end of September. If I were to hazard a bet, I would go with Patrick's prediction for the 2011 melt.

    Brilliant! Thanks Vaughn.

    I'd been hanging out for that PIOMAS update for so long, I just about given up checking. Got a few months of data to add in now....

    Patrick:

    Glad to see you back.

    It is difficult to tell exactly what your forecast for the 2011 minimum is. Could you please quantify it in a fashion that makes it possible to verify your analysis against a specific third party measure?

    I do not find ice free at the north pole to be particularly meaningful if there is 2.5 million km2 of ice cover per the Cryosphere Today graph for the Central Arctic Basin. This may be "ice free" to you, but if I can see ice cover in the Modis image andCryosphere Today reports more than 2 million km2 in the central Arctic basin, that is not ice free to me.

    I see no data in the information provided from the various sources above that shows that the thickness of first year ice is declining at a rate that would make the Arctic decline below an extent/area per NSIDC, JAXA or Cryosphere Today of 2 million km2 any time soon.

    The volume data being discussed above may only be showing that the Arctic is becoming ice free of thick multi-year iice. The volume trend line for first year ice may not be as steep as the trends being reported by the PIOMAS model anomaly chart.

    While the Arctic appears to be headed for an ice free state at the minimum, I do not see that you have provided sufficient data that proves this. Your discussion of the Fram Strait and Nares Strait lacks quantitative measures. It is not clear that the Nares Strait with its narrow gap or the Northwest Passage have the capacity to significantly alter ice export beyond levels that we are already experiencing. The Fram Strait is the major player in the export of ice. If you want to use this avenue as your method of depleting the Arctic of ice, please provide a quantitative indicator of the rate of increase that must occur in 2011 over the rate of export that has occurred over the last four years.

    As for Atlantic water heat and Ekman transport, these only matter to the extent they impact the first meter of sea water. To the extent they are heating up the water temperature below the first meter or so in which the ice resides, they may become the engine of future climate change, but they do not melt the ice.

    My verifiable prediction is that Arctic ice extent/area at the minimum using NSIDC, JAXA or Cryosphere Today will be above 2.5 million km2 in 2011, an area about 1.5 times Alaska.. This is not ice free.

    logicman
    Will: many thanks for your comment and queries.

    I am in process of writing my first March update, so please excuse the brevity of my response here.

    We are starting the melt season with almost the same area/extent of ice as in March 2007.  However, the volume is less, there is much less ice >1 year old and it is already highly fragmented - on a geographical scale.

    Last year, older ice melted out in the Canadian Archipelago, to be replaced by floes of older ice which are currently embedded in 1st year ice.  A repeat of that behavior would result in the loss from the Arctic ocean via Fram, Nares, NWP and the various channels in the archipelago of virtually all remaining ice older than 1 year.

    By September I consider it probable that the remaining ice will be mostly confined to the northern shores of Greenland, the Canadian archipelago, Nares Strait and northern Baffin Bay.  That would leave the ocean areas which are far from land virtually ice free.  I'll provide a chart in my update to make this clear.

    Thanks for the 'welcome back', and thanks for all of the interesting points you raised in discussions while I was away.
    Pagtrick:

    I have to agree with you that the Modis and ASAR Greenland images look like choppy ice.

    Just a note, I thought I remember seeing NSIDC report that a lot of thick ice disappeared in the Beaufort Gyre in 2010. I do not think it will be possible to duplicate this volume decline and the Canadian Archipelago volume decline you describe friom 2010 in 2011, there is just not enough thick ice to work with to create this large a drop.

    While total volume is down, I am not convinced that the volume and thickness of first year ice is down that much. The big difference in volume may be attributable to the decline of thick multi year ice which is down substantially from March of 2007

    Based on my limited knowledge, it looks like wind and weather will determine if we see the situation you describe.

    I do not think we will know what kind of September minimum to expect until July 1 and I will be watching the central Arctic Basin on Cryosphere Today to see how far below 4 million km2 it goes..

    Time will tell.

    Have you been able to spot the Petermann-Lockerby ice islands in Baffin Bay?

    I will keep my eye on Petermenn Fjord. Looks like it did not freeze over in the area in front of the tongue this winter.

    Vaughn A:

    Given the depletion of thick multi year ice that occurred at the September 2010 minimum (see the NSIDC October 4, 2010 report) I think you are making too much of the volume being 1,000 km3 below last year as an indicator that the Arctic will be ice free in 2011. The NSIDC reported a record low ice extent in February 2011. With both of these factors in operation, it is remarkable that volume is only 1,000 km3 below last year. I think this indicates that first and second year ice volume and thickness may be more robust than last year.

    First and second year ice thickness may be doing just fine even though thick ice older than 3 years has been nearly swept from the Arctic. I see this as a sign that the Arctic will not become ice free in 2011. You should compare the ice decline in 2010 to prior years, as I suspect that 2010 had an unprecedented volume decline that will not be repeated in 2011. There is just not a sufficient supply of thick ice to be transported or melted in 2011 to create the kind of volume decline in 2011 which occurred in 2010.

    At this point, it appears that first and second year ice is fairly robust in the Arctic basin above 80 degrees north even if ice below 75 degrees north is showing significant decline and open areas.

    It is still too early to know for certain, but the ice volume figures may be a sign that all is well with first and second year ice, not a sign that 2011 will be ice free. While ice below 75 degrees north is showing the impact of global warming, it does not appear that ice in the central arctic basin above 80 degrees is being depleted at a similar or sufficient rate to create an "ice free" Arctic in 2011. Other than the Barents Sea ice, which does not move into the central Arctic basin and which does not make a significant contribution to the September minimum ice extent, how much loss of ice extent has occurred in the Arctic Basin on the Cryosphere Today Charts?

    Looks like zero decline to me.

    Won't the ice above 80N just move wherever the wind blows it once the ice below 80N has melted ? I'm having trouble understanding why you think central basin ice will be special in late summer once the southerly ice has melted out.

    Will, I was pretty much thinking along the lines of Mike Hilson. Also once southerly ice has melted, and if in fact as you say it is thinner it will allow water and air temperatures to warm significantly at an earlier date in the more southerly areas as well. Air moves rapidly and would likely warm colder regions more than normal due to it's closer proximity. The water could easily flow under the ice edge melting more as well.

    Let's consider a hypothetical situation for a moment. Assume for a moment that the albedo is 80% over a particular area of ice and these conditions cause the air temperature to rise just to a point where no additional water freezes or ice melts. Then a storm blows through, stirs up the area, breaks up the ice and reduces the albedo to 60%. This will effectively double the solar energy available for heating. A large portion of the additional energy will go to melt the ice, warm the water, and warm the air with a very high portion of the additional energy eventually melting the ice in that particular hypothetical area.

    I suggest that due to what looks to be highly fractured ice this year that this effect will be particularly troublesome.

    Also, I didn't say that I thought all of the Arctic Ice would melt this year, just that the way the volume numbers were coming out we would be down to about 2000km^3. This is still a fairly significant amount of ice and spread thinly could still cover 2m to 3m km^2.

    At this point the debate about the future of Arctic sea ice really comes down to differing interpretations of what is happening with the ice volume. Assuming the PIOMAS model results continue to be in the right ballpark (they were confirmed through 2007 by ICESat and Cryosat should soon be able to tell us if current values are accurate) what we've seen is September ice volume dropping from about 10,000 km^3 in 2005 to 4,000 km^3 in 2010.

    If we were to assume that this volume loss was entirely due to a heat imbalance melting the ice then we would expect the trends to continue and Arctic sea ice volume would hit zero in about 3 years.

    On the other hand, if we were to assume that the volume loss was entirely due to export of older/thicker ice out of the Arctic then we would expect to see the volume loss level off at a value not much below the 2010 results as the fraction of the tiny portion of thick ice remaining which gets exported each year approaches the value of the new multi-year ice created each year.

    Obviously, in reality the volume decline is being driven by both of these factors and thus the debate is really over which is dominant. Given that in 2010 large portions of multi-year ice were pushed up into the Arctic basin far from any of the export sites and were then observed to melt out I think it is clear that we have reached a point where only the thickest and least mobile ice along the northern edge of the archipelago and Greenland is 'safe'... and even that will continue to be broken up and torn away by currents as it has been each of the past few years. As the amount of that thick ice continues to decline the energy which had been going into melting it will instead result in further reductions in extent of thin new ice. Thus, I think the rate of volume loss will soon slow, but volume will continue to decline and soon reach a point where large ice extents cannot be maintained... essentially melting down to just the remaining thick ice along the archipelago each year.

    It is also worth noting that maximum annual ice volume has been declining at nearly the same rate as minimum volume for decades now. It will be interesting to see whether that decline continues after the next few years when the minimum value stabilizes somewhere between its most recent value of 4000 km^3 and 0. I'm guessing it will, again on the view that more ice melting / less forming (rather than export) is responsible for most of the volume decline.

    MikeCrow
    I have an alternate theory, Not that I really think I'm right, only it's a possibility and this will put it out there for comments.

    North America (well at least around 41N -81W) has been cold the last couple years, and this winter we've had more snow than I can remember for a long time. But further North it's been warmer than normal (this doesn't mean it hasn't been cold though).

    What if this is a cooling mechanism? Warm waters oscillate through the ice in the Arctic, the ice melts. But darker warmer surfaces radiate heat better than snow/ice do. All of the incoming radiation even in the summer comes in at a shallow angle, a large portion of the horizontally polarized light will reflect off the ocean as glare, back into space. Patrick, that NASA web site you and Helen were talking about has some great energy budget images that show the poles cooling the planet even during that hemispheres summer.

    So, what this might be doing is cooling the oceans. If the La Nina's cold water displaces warm pacific water, some of that warm water could flow into the arctic, where's it's higher than normal temperatures would cool faster than normal.

    (Edit) Oh, I forgot to add that CO2 is absorbed by cold water (only for some of it to be released in areas of warmer water), This could also increase CO2 absorption (more open cold water). Higher concentrations in the cold return water might then allow more co2 to defuse into the permanently cold deep water. So not only might this increase arctic cooling, it might also reduce atm co2.

    Now before you jump up and say the CO2 will prevent this, let me note I live out of the city, and I've measured +25F temp drops 6-8 hr's after sunset on clear nights, While on cloudy nights temps drop very little.

    Just to be open, IMO the case of CO2 being the cause of most of the recent changes is flawed, and mostly based on a very broken Model.
    Never is a long time.
    Mi Cro Permanently cold in the deep ocean?

    Well it's cold-er than the rest, but it can still warm. And there is a lot of it, though "a lot" is a bit feeble for referring to the vast quantities of water involved. http://www.skepticalscience.com/billions-of-blow-dryers.html gives a summary of the latest detection of deep ocean heat.

    As for more CO2 into the oceans, the acidification rate is already stressing reefs and other ocean life. I'm more interested in seeing if we can find ways to get less rather than more into that environment.

    MikeCrow
    Well, yes it can be warmed, but I'll pose 2 points to this argument.

    First, Hundredths of a Watt/Sq M is an incredibly small amount of energy, You can hold a 7W night light in your hand which is much smaller than a sq meter, and the 7Watts is 100 times more powerful. And that's still 14 times the entire missing energy mentioned in your article.

    Second, over the last some 130 years, sea levels have risen ~ 8", since Satellites started taking the measurements (around 1970) sea levels have risen ~2.5".
    Oceans temps are reported as having increased ~.6C over the same period. I did some calculation, iirc 1 degree C rise of the first 100 M of Ocean water would increase sea levels a little over an inch. Which if you applied .6 C to the first 300 Meters (the thermocline), would increase sea levels ~2.5". The entire amount of actual measured sea level change.

    This puts a limit on how much heat the oceans could have possibly absorbed. If 1/3 to 1/2 of the increase was from melt water like I've read, that reduces the amount of captured heat further.

    Lastly, how much capacity for CO2 does the oceans have? Based on diffusion rates for CO2 into cold water it has the ability to absorb some 4,000 times the entire 600-700GT carbon cycle. Currently the oceans process ~90-100Gt Co2/year, absorbing co2 at the cold polar regions, exhaling CO2 in the warm tropical waters. But less co2 is exhaled than is absorbed. This could very well be a self regulating process for CO2 (and could explain much of the missing CO2), and it could indicate that the rise in atm CO2 is from a warming world, not humans.

    Never is a long time.
    Hi Patrick

    Today's sat image from DMI shows clearly the cracks or as you will fissures on the Petermann glacier:

    http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/201103100024.ASAR.jpg

    logicman
    Thanks, Espen.  I check the Kane and Kennedy images frequently.  The one you linked shows an apparent double fissure below the main one.  That is an image-processing artifact: there is just the one fissure where two are shown.

    Watch the Kane ASAR image sequence and compare to the Arctic mosaic images.  Watch for a rapid melt-out of ice in Kane Basin.  It would normally be a mix of various ages, but this year you can see a clear demarcation between 1st year ice area and older ice area behind the ice bridge.
    logicman
    Thanks to all for the comments.  I'll try to cover points raised in my updates.

    My March update #1 is nearly ready, but Mother Nature insists that I add some current data to keep my observations accurate.  :)
    Another feedback that I suspect contributes to breakup and melt is methane fountains from the seafloor. There is a weak temperature gradient of warming with depth in the Arctic, but it is stable because there is a salinity gradient which makes the water denser with depth. See "Dynamics in the Deep Canada Basin, Arctic Ocean, Inferred by Thermistor Chain Time Series" TIMMERMANS et al and http://en.wikipedia.org/wiki/File:Arctic_sea_temperature_salinity_plot.svg. The decay of methane hydrates is causing bubbling of gas at the edge of the hydrate stability zone, and this acts to drive the slightly saltier, slightly warmer bottom water to the surface. http://planetearth.nerc.ac.uk/images/uploaded/custom/Plumes-example-c2.jpg and "Escape of methane gas from the seabed along the West Spitsbergen continental margin" Westbrook et al.
    Some years there is a line of ice breakup along the Siberian Shelves that I think corresponds to the edge of the hydrate stability zone. In http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=05&fd=19&fy=2004&sm..., note thyen lines of thin ice running southwest from the Severnaya Zemlya across the Kara Sea, and across the Laptev sea from Novaya Zemlya.

    logicman
    Brian:  thanks for your contribution.  I'll check out some past MODIS images of those areas when I find time.

    Here's a link to an article on this topic which uses the image you linked to:
    http://www.sciencedaily.com/releases/2009/08/090814103231.htm
    logicman
    The update mentioned in this comments thread was posted March 08 2011 -

    Arctic Ice March 2011 - Update #1
    Hi Patrick,

    You say your successes of 2010, but you only said 2 things about the Arctic and only one of those was proved right, so that is a 50% hit ratio.

    logicman
    AndyW: I made a little more more than two predictions.

    2010:
    Many hottest weather records are broken in northern hemisphere.
    Summer arctic ice at record low in extent.
    By September the Arctic Ocean is freely navigable by both the northern sea route and the north west passage.
    Global Cooling : Beyond Parochialism
    Referring to my prior article and prediction for May, I said this in June:
    I have no doubt that by the end of this month, May 2010, there will be much less sea ice than there was in May 2007.
    I have no doubt either that the anti-science propagandists will continue to insist either that the ice is recovering or that Arctic melt is perfectly normal.

    I claim that I was right on both counts.
    chatter_box/arctic_ice_june_2010
    Posted June 02 2010:
    May 31 2010 - North West Passages.
    The ice between Parry Channel and McClure Strait - between the melt fronts indicated by the green lines - has persisted for some time.  It is likely, in my opinion, that opposing tides or currents have caused a consolidation here as an ice bridge.  Until that ice is gone, the movement of ice fragments in the channels will be very restricted.  I expect more melting in this area over the next month, but expect the ice bridge to remain for about 2 to 4 weeks more.
    http://www.science20.com/chatter_box/arctic_ice_june_2010
    The ice bridge referred to broke up and by July 13th it was greatly fragmented and in process of being flushed away.

    My prediction for the end of season 2010 extent was wrong - I had expected less than 4 million km2

    My Petermann Glacier predictions were spot on:
    Judging by previous behavior and by the forces which will act on a more mobile ice tongue, I predict some dramatic calving this year. 
    Arctic Ice July 2010 - Update #3:

    July 22 2010:
    The Petermann ice tongue looks primed to lose a few fairly large floes any day now.
    Arctic Ice July - Update #4

    Having predicted the calving I was watching satellite images daily.  I published the news of what I had predicted - a dramatic calving - August 05 2010. Arctic Newsflash! Petermann Ice Tongue Loses Huge Chunk

    Given the timescales over which glaciers do their thing, I hope you will accept that 'any day now' applied to a 14 day period is not badly off target.  I had expected the calving as to area, but not as a single chunk.  The ice island later broke into chunks similar to the shapes I had projected before it calved.

    I'll stop there.  That's enough bragging for one day.  ;-)
    So, how's my score now?