News from the Ice Wars:An Occasional Bulletin

The Northern Front

Darker snow surfaces absorb more sunlight and melt quicker. This effect is visible in Greenland. Box et al.,"Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers," The Cryosphere, v6, pp821 et seq., doi:10.5194/tc-6-821-2012 state: " Thus, intraseasonal summer albedo variability exceeds 0.50 over parts of the ice sheet where a snow layer ablates by mid-summer, exposing an impurity-rich ice surface ..." Prof. Box is now investigating soot from North American wildfires as a factor in the darkening of Greenland. At his web site meltfactor.org, he has albedo data through half of 2013:


Variation in Greenland albedo from 2000 to 2013

Note the steady decline, then the precipitous drop in 2012. Box notes that "...an additional 24 EJ is sunk into melting in 2011 compared with 2000, equivalent with a 72 Gt increase in melt water production over the period." By comparison, 360 Gtonne would case a 1mm rise in sea level if it all flowed to the ocean.

The extraordinary melt in 2012 was captured in a series of infra red images (ASCAT) taken from space.
Greenland infra red image 29 May 2012 Greenland infra red image 18 jun 2012 Greenland infra red image 09 jul 2012 Greenland infra red image 10 jul 2012 Greenland infra red image 11 jul 2012 Greenland infra red image 12 jul 2012 Greenland infra red image 13 jul 2012 Greenland infra red image 14 jul 2012 Greenland infra red image 09 jul 2012
The images were taken on 29th May,18th June,9th July,10th July, 11th July,12th July,13th July,14th July,and the 18th of July.

The following animated GIF shows the sequence from the 29th of May through the 6th of September.

Greenland infra red animation from 29th May to 6th September

What is shown above is nothing less than the entire surface of Greenland melting. This has never been seen before.

UPDATE

A hard rain's gonna fall on Greenland, helping it melt in place. Oh, wait it already happened. Neff et al., doi: 10.1002/2014JD021470 document exactly that happening on July 8th through 12th. Fig 3 panels interspersed with ASCAT images. The redder, the wetter.

Hard rain falling on Greenland, July 2012

Behold the chakra of doom. A video of the of the arctic and subarctic in infrared for 2012 may be found avi, flv or mp4. The mp4 seems to have the best detail. ImageMagick and ffmpeg are wonderful things.

Greenland surface mass balance has started to dominate glacier discharge since 2006.

Current projections of the fate of the icesheets are uncertain. Projections using linear, semi-empirical models project a range of 0.5 to 2 meters by 2100. These do not and cannot take into account nonlinear processes destabilizing the ice sheets.

The page this one supports is here

Some more posts on Greenland are linked from here and new bedrock maps here