New Study of Antarctic Ice Loss (not looking good)

[Viking12]

From Greg Laden's blog:

The amount of ice lost to the sea from Antarctica has increased by 75 percent in the last 10 years. This is the result of an increase in glacial flow. It had previously been thought, and perhas was the case, that Greenland ice loss outpaced the Antarctica. This is no longer the case.

An article coming out in the next issue of Nature Geoscience, by Rignot et al ("Recent Antarctic ice mass loss from radar interferometry and regional climate modelling") is the most detailed study of this phenomenon to date.

There are two factors that affect the flow of ice into the sea at the edge of the southern continent. One is the amount of snow that falls across the continent, which might increase the total amount of water trapped in glacial ice, or might increase the speed of glacial movement towards the sea. The other is how rapidly the glaciers slide into the sea at the glaciers' "grounding sites,"

Global warming may have increased the amount of precipitation in Antarctica, which could increase the total volume of water trapped in this mass of ice. This would partially offset sea level rise caused by glacial melting in the Arctic and in mountain glaciers. However, warmer seas surrounding Antarctica and warmer air temperatures can cause the melting edge of the glaciers to mlt faster. When the grounding edge of the glaciers falls apart due to warm air or water, the mass of the glacier behind this leading edge moves more quickly to the sea.

http://scienceblogs.com/gregladen/2008/01/new_study_of_antarctic_ice_los.php

[hatrack]

1. Whoops! Can you say "Faster Than Expected"?

Good! I knew you could!

[tom_paine]

2. I'm not going to say it. I'm just not. Holding my breath now...

n/t

[XemaSab]

5. I can!

:D

[pingzing58]

3. I'd love to see the center of power New York under water, I'm sorry don't mean to offend!

[OKIsItJustMe]

4. The letter itself can be found here

http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo102.html

Letter abstract

Nature Geoscience
Published online: 13 January 2008 | doi:10.1038/ngeo102

Recent Antarctic ice mass loss from radar interferometry and regional climate modelling

Eric Rignot^1,2,3, Jonathan L. Bamber⁴, Michiel R. van den Broeke⁵, Curt Davis⁶, Yonghong Li⁶, Willem Jan van de Berg⁵ & Erik van Meijgaard⁷

Large uncertainties remain in the current and future contribution to sea level rise from Antarctica. Climate warming may increase snowfall in the continent's interior^1,2,3, but enhance glacier discharge at the coast where warmer air and ocean temperatures erode the buttressing ice shelves^{4,5,6,7,8,9,10,11}. Here, we use satellite interferometric synthetic-aperture radar observations from 1992 to 2006 covering 85% of Antarctica's coastline to estimate the total mass flux into the ocean. We compare the mass fluxes from large drainage basin units with interior snow accumulation calculated from a regional atmospheric climate model for 1980 to 2004. In East Antarctica, small glacier losses in Wilkes Land and glacier gains at the mouths of the Filchner and Ross ice shelves combine to a near-zero loss of 4±61 Gt yr^-1. In West Antarctica, widespread losses along the Bellingshausen and Amundsen seas increased the ice sheet loss by 59% in 10 years to reach 132±60 Gt yr^-1 in 2006. In the Peninsula, losses increased by 140% to reach 60±46 Gt yr^-1 in 2006. Losses are concentrated along narrow channels occupied by outlet glaciers and are caused by ongoing and past glacier acceleration. Changes in glacier flow therefore have a significant, if not dominant impact on ice sheet mass balance.

1. University of California Irvine, Earth System Science, Irvine, California 92697, USA
2. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
3. Centro de Estudios Cientificos, Arturo Prat 514, Valdivia, Chile
4. University of Bristol, Bristol BS8 1SS, UK
5. Institute for Marine and Atmospheric Research (IMAU), Utrecht University, 3584 CC Utrecht, The Netherlands
6. University of Missouri-Columbia, Columbia, Missouri 65211, USA
7. Royal Netherlands Meteorological Institute (KNMI), 3732 GK De Bilt, The Netherlands

Correspondence to: Eric Rignot^1,2,3 e-mail: [e-mail]