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    Arctic Tipping Points - #7: Can The Arctic Recover?
    By Patrick Lockerby | June 23rd 2010 04:57 AM | 19 comments | Print | E-mail | Track Comments
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    Arctic Tipping Points - #7: Can The Arctic Recover?


    In Arctic Tipping Points - #6: Are We There Yet? I attempted to show that there are multiple feedback mechanisms which are capable of causing a composite positive feedback effect in which Arctic sea ice once reduced beyond a limit will disperse very rapidly and will fail to recover.

    Since I published that Article - April 29 2010 - I have investigated the matter further.  Current satellite data and historical reports combine to suggest that this year's Arctic sea ice loss will be the greatest ever seen in human history.

    Throughout human history the North West and North East Passages have been traps for ships and killers of men.  Prior to 2000 none of the passages was ever open from end to end.  The ice which blocks these passages once melted is - by definition - first year ice, hence easily melted.  That is a positive feedback.

    This summer, the Royal Canadian Mounted Police patrol vessel Nadon (temporarily rechristened the St Roch II) made a transit through the Northwest Passage — the shortcut between the Pacific and the Atlantic across the top of North America — and encountered very little sea ice along the way.

    Nature 408, 634-636 (7 December 2000) | doi:10.1038/35047263
    http://www.nature.com/nature/journal/v408/n6813/full/408634a0.html

    Jan Mayen and the Odden Ice Tongue

    The Odden Ice Tongue used to form between Greenland and the tiny island of Jan_Mayen, about halfway between Iceland and Svalbard.  It has not been seen since 1997.

    Jan Mayen Island and Beerenberg

    The Odden was most extensive in 1979, 1982, 1986, and 1997 and most persistent in 1988, 1989, and 1997 but did not appear in 1984, 1994, and 1995, suggesting decadal periodicity for the 20 year period.
    http://www.agu.org/pubs/crossref/2001/2000JC000204.shtml


    Odden Ice Tongue February 16, 1993
    Image source: http://earth.esa.int/...


    The Odden Ice Tongue was a seasonal bridge of ice from the Greenland coast to Jan Mayen Island, with an extended tongue beyond.  The tongue had two modes of formation.  The normal mode formed sea ice directly, rejecting salt into the ocean and driving part of the return circulation of the Atlantic conveyor.  A second mode formed a bridge of mainly older ice, rejecting less salt into the ocean.

    Both modes obstructed the egress of broken ice from the main ice cap via the Fram Strait.  The loss of the Odden has allowed warm water to flow further north and has removed an obstacle to ice loss by southerly drift.  The loss of the Odden is a double feedback.


    The Nares Polynya

    I wrote extensively about the Nares Polynya in Arctic Tipping Points - #4: The Broken Bridges Of Nares.  Here I present more images of the Nares ice bridges in past years and images of the current state of the ice in that region.

    The sequence of images below is taken from Rapidfire images 2002 to 2009


    July 19 2002 - ice blockages in Nares Strait..
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2002200/crefl1_14...


    August 30 2003 - slow ice export from Lincoln Sea into Nares Strait.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2003242/crefl1_14...


    July 30 2004 - two ice bridges block the strait.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2004182/crefl1_143.A2004182205001-2004182205501.1km.jpg


    July 01 2005 - entire strait blocked by ice bridges and ice jams.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2005182/crefl1_143.A2005182224001-2005182224500.1km.jpg


    July 01 2006 - Nares Strait almost entirely blocked by ice bridges and ice jams.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2006182/crefl1_14...


    July 13 2007 - ice begins to flow freely from Lincoln Sea.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007194/crefl1_14...
    Note: most of the ice in left of image is from Kane Basin, not the Lincoln Sea.


    July 01 2008 - most of the ice in the Nares Polynya is not from Lincoln Sea.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2008183/crefl2_14...


    July 01 2009 - a strong ice arch keeps the polynya virtually ice free.
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2009182/crefl1_14...


    Nares Polynya 2010

    There is a great deal of variability in the above images, all of which are from July, or later where July images are not available.  The images below, from June 22 2010 show how much more readily the ice is flowing from Lincoln Sea to Baffin Bay this year.  The flow is faster and earlier.


    June 22 2010 - ice flows freely from Lincoln Sea to Baffin Bay
    This resized image was taken from two images stitched together:
    http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c02.2010173...
    http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c03.2010173...


    The image below shows the granularity and mobility of the ice in greater detail.  Smaller floes make for an easier exit from the Arctic ice cap via Lincoln Sea and the Nares Polynya.


    June 22 2010 - Nares Strait and Petermann Glacier

    The Petermann Glacier ice tongue has a notched end and is not firmly attached to the walls of the fjord.  The next image shows more detail of the mélange - mixed bergs and sea ice - and the melt pools.

    Petermann Ice Tongue detail


    Humboldt Glacier and Kane Basin detail.
    At the bottom of the image is the Greenland ice cap.  The ice cap margin is specked with meltwater pools.  The blue area is sea ice, with speckles of white showing icebergs from the main calving front. To the left of that calving front the line of the glacier rarely changes.  I consider it likely that the ice sheet is grounded on rock which slopes up towards Kane Basin, except at the calving front.  Note the jagged lumps of ice, in contrast to the more rounded and granular sea ice in the other images.

    Ice which appears in satellite images as blue areas separated by white lines - I like to call it 'panel ice' - seems to be more robust than other ice.  Sea ice is often a mass of granular floes held together by new ice.  Predictably the new ice will melt or fracture first, rendering the whole ice mass highly mobile.  Panel ice tends to remain immobile longer than granular ice, and when it fractures it does so unpredictably.


    Some points for discussion:

    Historically, the main Arctic ice cap was less granular and less mobile. 

    Loss of multi-year ice was restricted by the Nares ice bridges and the Odden ice tongue.

    Loss of some multi-year ice is part of the natural Arctic ice cycle.  Ice loss creates gaps in which new ice can form.  The formation of new ice and the rejection of brine from young ice drive the thermohaline circulation.  Ice free summers may well alter thermohaline circulation patterns.

    In summer, the presence of sea ice can, by acting as an insulator, produce a temperature difference between air and ocean of up to 30oC.

    An ice free Arctic would produce air and sea temperatures substantially higher than normal.

    Before ice can form, the sea and air temperatures must drop: the summer heat must be radiated away.  After an ice free summer the Arctic winter freeze season will be shortened.

    Snow increases the albedo of ice and acts as a thermal blanket.  This delays ice melt in spring.  Before Arctic snow can settle, it needs ice to settle onto.  A delay in freezing brings a delay in snow cover.  After an ice free summer, ice will be thinner and will have thinner snow cover than normal.  This is another positive feedback.

    Conclusion:

    The loss of multi-year ice, the loss of the Odden ice tongue, the open Nares Strait, the granularity and mobility of the main ice cap: these factors taken together point to the likelihood that the Arctic has passed a tipping point with no realistic prospect of recovery.

    A warmer Arctic will mean a greater summer loss of ice from Greenland's many glaciers..

    References:

    Odden Ice Tongue
    Two modes of appearance of the Odden ice tongue in the Greenland Sea
    http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19990009390_1998435...

    http://www.nature.com/nature/journal/v408/n6813/full/408634a0.html

    http://www.agu.org/pubs/crossref/2001/2000JC000204.shtml

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VGC-3X7MKH9-8...

    Nares Polynya

    Ice Regime and Ice Transport in Nares Strait, Moira Dunbar
    http://pubs.aina.ucalgary.ca/arctic/Arctic26-4-282.pdf
    On checking the link, I found the file is now corrupt.  I have posted a copy here:
    Arctic26-4-282.pdf

    Fall Ice Drift in Nares Strait, as Observed by Sideways-Looking Radar, Moira Dunbar
    http://pubs.aina.ucalgary.ca/arctic/Arctic32-4-283.pdf
    On checking the link, I found the file is now corrupt.  Unfortunately I don't have a copy.


    Evidence for atmospheric control of sea-ice motion through Nares Strait
    http://www-hce.coas.oregonstate.edu/~rms/ms/NaresStraitGRLsubm_rev.pdf

    Nares Strait Hydrography and Salinity Field ...
    http://www.earth.ox.ac.uk/~helenj/work/publications/Berit1.pdf

    Comments

    Here's a link to an abstract about sea ice outflow thru the Nares Strait

    http://www.agu.org/pubs/crossref/2010/2009GL041872.shtml

    Patrick;

    Don't know if you've made a prediction for how much sea ice there will be at the minimum this year.
    However, the SkepticalScience site has a series of predictions. I added one in the comments of about 3.8 Mkm^2.

    http://www.skepticalscience.com/September-2010-Artic-Ice-Extent-Handicap...

    logicman
    Andrew: thanks for reminding me of the Kwok et al paper Large sea ice outflow into the Nares Strait in 2007.

    In 2007, ice arches failed to form. This resulted in the highest outflow of Arctic sea ice in the 13-year record between 1997 and 2009. The 2007 area and volume outflows of 87 × 103 km2 and 254 km3 are more than twice their 13-year means. This contributes to the recent loss of the thick, multiyear Arctic sea ice and represents ∼10% of our estimates of the mean ice export at Fram Strait. Clearly, the ice arches control Arctic sea ice outflow. The duration of unobstructed flow explains more than 84% of the variance in the annual area flux.
    http://www.agu.org/pubs/crossref/2010/2009GL041872.shtml

    A later paper showing that the 2007 Nares ice export was wind driven has been widely misrepresented to 'disprove' Arctic warming.  The reality is that colder weather produces a stronger and more compacted ice cap which is resistant to the fragmentaion which allows ice to flow into the Nares Strait.

    Ice export via the Nares in 2007 began about the first week of July.  This year, Nares export has been continuous and rapid since the start of April.

    I have already posted a prediction of 3.8 M sq. km. as an upper limit for this years lowest sea ice extent.  That is looking increasingly over-optimistic.
    Neven
    Patrick, this might interest you (if you don't know already): One of the NOAA webcams stationed at the North Pole seems to be showing a first melt pond.

    Snow increases the albedo of ice and acts as a thermal blanket.  This
    delays ice melt in spring.  Before Arctic snow can settle, it needs ice
    to settle onto.  A delay in freezing brings a delay in snow cover. 
    After an ice free summer, ice will be thinner and will have thinner snow
    cover than normal.  This is another positive feedback.


    Have you considered something like a lake effect snow due to all that extra moisture in the air? I don't have much of an opinion on it as of yet (will explore it further if we get to record levels this year), but it might also have an influence on precipitation in the NH and consequently the amount of albedo.
    logicman
    Neven:  it's not possible to judge the area of open water from that web cam.  Polynyas and leads are common throughout the ice cap.  Isolated open water isn't significant.  On the other hand, areas of ice which are highly fragmented and riddled with surface meltwater pools, leads and polynas are historically rare, but are widespread this year.

    You are ahead of me.  :-)  Lake effect snow is likely to be very significant in the near future along all Arctic coasts.  I have an article planned.
    Neven
    You are ahead of me.  :-)  Lake effect snow is likely to be very significant in the near future along all Arctic coasts.  I have an article planned.

    Fantastic, I'll be waiting expectantly. We'll talk about it then.
    Lake Effect Snow!

    I just so happen to live in a Lake Effect snow area...

    So, First let us ponder that the Arctic Ocean is an ocean not a lake.
    Second, Lake effect snow happens because the Great Lakes become very warm and cold air blows over them.
    Towards the end of winter, when the lakes cool off, lake effect becomes less significant.
    It's also a function of the elevation change off the lakes and requires a low pressure system for a lot of lift.
    These areas where these conditions occur are limited (but just so happen to be very near where I live).

    So, while there may eventually be some areas near the Arctic that experience enhanced precipitation (snow) due to the additional moisture from a melted Arctic, I'd be careful about describing it as "Lake Effect". Also, I suspect that the warming climate will allow a lot of moisture from southern regions to travel further north than they do now. This will probably be more significant than the moisture from the Arctic itself. Water at just above the freezing point doesn't release anywhere nears as much moisture to the atmosphere than warmer waters do.

    Anyhow, that's my impression.

    logicman
    ... while there may eventually be some areas near the Arctic that experience enhanced precipitation (snow) due to the additional moisture from a melted Arctic, I'd be careful about describing it as "Lake Effect".
    Agreed, Andrew.

    It might better be described as an 'extended open water effect', but I think we are stuck with 'lake effect'.

    The big question is: 'which Arctic land areas will see the greatest increase in snowfall if the Arctic, as an area of open, warm water, becomes the source of lake effect snow?'  At the moment, any answer to that question would be a wild guess.  We need more observations of the changing Arctic climate.
    The IPCC has a number of models and one of the most robust findings is that there will
    be a dramatic increase in the amount of winter precipitation in the subarctic.

    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html

    The trend towards more winter precipitation Is already noticeable.
    Our local TV Weatherman has noticed it too. The lakes are warmer and we are getting more storms.
    So, it is not from the Arctic itself. Rather it's from storms gathering moisture from the south.

    Anyhow, we are tending off topic here.

    This morning the Cyrosphere Today site is showing an anomaly of -1.707Mkm^2.
    That is huge!
    The loss of sea ice over the 2 weeks has been dramatic.
    Not sure if it's a record. However, usually this happens closer to September.

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png

    This AM, the arctic sea ice anomaly is -1.927 MKm2.

    That's an anomalous loss of 0.22 MKm^2 in 1 day!!!!!!!

    Incredible.

    logicman
    This AM, the arctic sea ice anomaly is -1.927 MKm2.

    That's an anomalous loss of 0.22 MKm^2 in 1 day!!!!!!!

    Incredible.

    Wow!  Thanks for highlighting that astonishing fact, Andrew.
    logicman
    Neven's comment about the web cans near the North Pole got me interested in checking updates.

    This image from June 26 2010 is quite remarkable.

    The sky is so clear that you can see the land1 in the distance.

    What is even more remarkable is that, even on a clear day, you would not expect to see so far due to intervening pressure ridges and jumbled ice.

    http://psc.apl.washington.edu/northpole/webphotos/noaa2.jpg



    [1] - if the webcam was truly at the North pole, then the features on the horizon might be pressure ridges.  The camera has drifted far from the pole and is consequently nearer the coast.  Mirage effects can make distant objects appear to be much nearer.

    Many an Arctic explorer has reported land where there was none, so I may be wrong in identifying the feature as land.  Even so, such a large extent of flat ice is unusual.

    Current location map for PAWS buoy:

    http://psc.apl.washington.edu/northpole/DriftTrackMap.html
    Neven
    Patrick, that is an extremely interesting observation (I think), ie the view not being blocked by ridges.

    If this would be the case, what does it say about the ice over there? Is it a sign of the ice being thick and not 'ridgeing' much? That's counterintuitive. Is it a sign of ice being thin and therefore ridges not becoming high? That sounds better, but isn't logical either. There should mostly be multi-year ice out there, right?

    I've checked in Google Earth, and I think the distance to the coast is about 250-300 km. That is very far away, but until recently I have lived in the South of Germany and I could easily see the Alps from a distance of 150 km on a clear day. OK, the Alps are probably a bit higher than Greenland or Ellesmere Island... ;-)

    Do we have any way of knowing in which direction the camera is pointed?


    BTW, maybe I'm being a bit premature here, but things really seem to be accelerating at the moment: http://neven1.typepad.com/blog/2010/06/whoa-arctic-basin.html
    logicman
    Neven, I like the animation.

    http://neven1.typepad.com/blog/2010/06/animation-4-mcclure-strait.html

    On June 2 2010 I wrote, in Arctic Ice June 2010:
    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.
    This prompts the question: do I know what I'm talking about, or am I a lucky guesser. ;-)

    As to the web cam picture - I was wrong.  I should never put my thoughts in writing when I have a headache.  On looking again, I see from the perspective that the camera is only about 4 to 5 feet off the ground.  That puts the horizon at around 3 land miles, so the feature on the horizon has to be ridges.

    Neven
    I should never put my thoughts in writing when I have a headache.


    That's what I thought too when I woke up this morning (after a very long night) and realized that I actually wrote the blog post title 'Whoa, Arctic Basin!'. I changed the title straight away.

    Let's just say I was very tired and got a bit carried away by the drop on that CT graph, the melting ponds on NOAA webcam 2, topped off by the disintegration of the ice bridge in McClure Strait. :-)
    logicman
    Some more information on Jan Mayen:

    As I wrote above, the Odden Ice Tongue used to form fairly regularly between Greenland and Jan Meyen Island and beyond.  It last formed in 1997.

    The Odden was most extensive in 1979, 1982, 1986, and 1997 and most persistent in 1988, 1989, and 1997 but did not appear in 1984, 1994, and 1995, suggesting decadal periodicity for the 20 year period.

    It is interesting to check those dates with temperatures in the NASA GISS surface temperatures graph.  Note the dramatically reduced variation in temperatures of recent years.

    Image source:
    http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=63401001...


    I have with great interest read your articles about the Melting of arctic ice, which have interested me for some years now. But I am chocked to see the extend of this years melting season, there is hardly no pure ice (100%) left in the arctic sea area, it more or less rotten ice (as we call it Norwegian) all over the place, it will interesting to see how much will left in August - September 2010? I will follow your comments and articles with great interest. Best regards the amateur scientist.

    logicman
    Espen: thanks for the kind comment.

    My latest update for ice watchers is now posted - Arctic Ice July 2010
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