Arctic sea ice thread

[Oddball]

September is usually the month that the Arctic sea ice reaches its furthest retreat. So far, it appears that this year is well on its way to possibly seeing a record loss of ice in the arctic. Although the melt began quite late this year, the ice has retreated a pretty large amount during the past few weeks:

http://www.ijis.iarc.uaf.edu/seaice/...a_Ice_Area.png

http://iup.physik.uni-bremen.de:8084/amsr/ice_ext_n.png

http://www.ijis.iarc.uaf.edu/cgi-bin...tor.cgi?lang=e

What's even more interesting is that the volume of ice in the arctic appears to be unusually low for this time of the year:

http://psc.apl.washington.edu/Arctic...alyCurrent.png

There may be many valid explanations for this. Anomalous winds? Satellite errors? Global warming caused by El Nino and/or rising CO2 levels? Who knows. Whatever the reason, the Church of Doom may soon have many new members.

edit: Yes, I know that there's already a global warming thread, but I think this topic deserves its own thread since there may be many updates to it as the summer progresses.

So, will the melt continue at this rate, or will it slow down a lot? Stay tuned.

[Oddball]

A week and a half later, the Arctic ice extent, area, and volume continue to be at or near record lows for this point in the season. The northern hemisphere is also approaching peak insolation, and the sun is close to the highest point it'll ever get above the north pole horizon. The much hyped albedo feedback occurs around this time (open water absorbs more solar energy than ice, which warms the oceans and leads to further ice loss, creating more open water that absorbs...and so on). If there's more ice than usual in September, it could mean that albedo feedback isn't that big of a factor, which would deal a heavy blow to some of the more extreme global warming predictions that assume this to be a strong feedback.

On another note, sea ice levels do tend to cluster at this time and in November. The ice levels in March and September vary quite a lot from year to year, but the ice levels in June and November are roughly the same each year.

[Andi47]

False-color image of the arctic sea ice: http://iup.physik.uni-bremen.de:8084..._AMSRE_nic.png

...and of the antarctic sea ice: http://iup.physik.uni-bremen.de:8084..._AMSRE_nic.png

(updates a few times every day, but I don't know exactly how often.)

[Historian]

Some weather maps of the arctic area:

http://www.uni-koeln.de/math-nat-fak...tic_world.html

http://www.esrl.noaa.gov/psd/map/ima...w/ens_jsw.html

http://www.athropolis.com/map2.htm

[Oddball]

The melt season is nearly over, and 2010 is in a photo finish with 2008 for the second lowest extent and area.

This area graph puts 2010 at a tie with 2008:
http://www.ijis.iarc.uaf.edu/seaice/...a_Ice_Area.png

while this graph shows 2010 a tiny bit higher than 2008 levels:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.area.arctic.png

As for extent, this graph shows 2010 matching 2008:
http://iup.physik.uni-bremen.de:8084/amsr/ice_ext_n.png

while this graph has 2008 in the lead by a small amount:
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent_L.png

There are only a few days of melt to go, assuming we haven't reached the minimum already. I wonder how 2011 will turn out.

BTW, someone has made a pretty detailed blog on Arctic ice:
http://neven1.typepad.com/blog/