Arctic update: Scientists say global warming continues to melt Arctic

Update: Warming continues to affect far north

WASHINGTON — Global warming is messing with the planet’s thermostat.

That warning came Thursday from Richard Spinrad, head of research at the National Oceanic and Atmospheric Administration, in releasing the annual update of science’s Arctic report card.

Warming temperatures continue in the polar north, changing wind patterns, melting sea ice and glaciers and affecting ocean and land life, the report said.

The Arctic is a sort of natural regulator in terms of the amount of heat stored in the ocean and ice, “especially the loss of sea ice is messing with that thermostat for the whole globe,” Spinrad said at a briefing.

A particular problem is the disappearance of old, thick sea ice that has been present for thousands of years, added James Overland of NOAA’s Pacific Marine Environmental Research Laboratory.

“It’s very difficult to get that (ice) back,” he said.

Among the findings of the update:

—Air temperatures over the Arctic Ocean reached an unprecedented 7 degrees Fahrenheit (4 Celsius) above normal in October-December of 2008.

—There is evidence that the higher air temperatures are causing changes in the air circulation in both the Arctic and northern mid-latitudes.

—The area covered by sea ice this summer was 25 percent below the average from 1979 to 2000 and was the third since satellite records were begun in 1979.

—The melting ice resulted in an unprecedented amount of fresh water in the surface layer of the Arctic Ocean.

—The amount of land covered by snow in the winters of 2007-08 and 2008-09 continued the trend toward shorter snow seasons due to earlier spring melt, although there is considerable annual and regional variability.

On the Net:

Arctic Report Card: www.arctic.noaa.gov/reportcard/