NOAA: Arctic Report Card 2011

December 5, 2011

NOAA Arctic Report Card:

Atmosphere – Higher temperatures in the Arctic and unusually lower temperatures in some low latitude regions are linked to global shifts in atmospheric wind patterns.

Sea Ice & Ocean – A shift in the Arctic Ocean system since 2007 is indicated by the decline in ice age and summer extent, and the warmer, fresher upper ocean.

Marine Ecosystems – Since 1998, biological productivity at the base of the food chain has increased by 20%. Polar bears and walrus continue to lose habitat in Alaskan waters.

Terrestrial Ecosystems – Increased “greenness” of tundra vegetation in Eurasia and North America linked to increase in open water and warmer land temperatures in coastal regions.

Hydrology and Terrestrial Cryosphere – Continued dramatic loss of ice sheet and glacier mass, reduced snow extent and duration, and increasing permafrost temperatures are linked to higher Arctic air temperatures.

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The report also notes the reversal of the normal Arctic Oscillation pattern, that has brought severe arctic cold to the eastern US and Eurasia over the last two winters, while at the same time sending record warmth into huge areas of northern Canada, Greenland, and the Arctic Ocean.

In late autumn 2010 and early winter 2011 there was a continuation of the “warm Arctic-cold Continent” climate pattern that first appeared in winter 2009-2010, when an increased linkage between Arctic climate and mid-latitude severe weather occurred. This was due to changing wind patterns, which resulted in both warmer and colder regions in the sub-Arctic.

The cause for the increased exchange in the last two winters is a subject for further research into whether recent changes in the Arctic are involved, whether they are the result of extreme but random events, or a combination of these and other mechanisms.

 Christian Science Monitor:

Previous reports have been reluctant to pronounce a changed regime at the top of the world. But with nearly five years of additional observations and research in the region since the record-low summer sea-ice cover of 2007, the trends have become clearer, the researchers say.

“We’ve got a new normal,” says Don Perovich, a polar scientist with the US Army Corps ofEngineers’ Cold Regions Research and Engineering Laboratory in Hanover, N.H. It’s “a normal that has less ice, thinner ice, younger ice, a new normal where more light will be transmitted through the ice into the upper ocean. That has implications not just for the ice but for other components of the Arctic system.”

Changes the report tracks “have long been predicted,” notes Jonathan Overpeck, who is codirector of the Institute of the Environment at the University of Arizona in Tucson. “It is troubling how fast the change is proceeding. Of particular note is not just the sea-ice change, but the accelerating rate of Greenland Ice Sheet ice loss.”

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