Summit County Citizens Voice

Despite rapid monthly growth, Arctic ice extent continues long-term decline

Arctic sea ice grew at an above-average pace in February, 2012.

Monthly February ice extent for 1979 to 2012 shows a decline of 3 percen per decade. GRAPHIC COURTESY NSIDC.

By Summit Voice

SUMMIT COUNTY — Arctic sea ice extent grew at a faster than average rate, and spiked in late February, but despite spreading farther than normal on the Pacific side of the Arctic, the overall extent was lower than average. Thick multi-year ice continues to melt quickly, according to NASA researchers.

Overall, the Arctic gained 369,000 square miles of ice during the month. This was 188,000 square miles more than the average ice growth for February 1979 to 2000.

For the month, the ice extent averaged 5.62 million square miles, about 409,000 square miles below the 1979 to 2000 average extent, making it the fifth-lowest February ice extent in the satellite data record, according to the monthly update from the National Snow and Ice Data Center.

Including the year 2012, the linear rate of decline for February ice extent over the satellite record is 3 percent per decade. Based on the satellite record, through 2003, average February ice extent had never been lower than 5.79 million square miles. February ice extent has not exceeded that mark eight out of the nine years since 2003.

At the end of the month, ice extent rose sharply, as winds changed and started spreading out the ice cover. According to the National Snow and Ice Data Center, sea ice extent in late winter can go up and down very quickly, getting pushed together or dispersed by strong winds.

Ice extent usually reaches its annual maximum sometime in late February or March, but the exact date varies widely from year to year.

Continuing the pattern established in January, conditions differed greatly between the Atlantic and Pacific sides of the Arctic. On the Atlantic side, especially in the Barents Sea, air temperatures were higher than average and ice extent was unusually low.

February ice extent for the Barents Sea was the lowest in the satellite record as air temperatures over the Laptev, Kara and Barents seas ranged from 7 to 14 degrees  above average at about 3000 feet above sea level.

In contrast, on the Pacific side, February ice extent in the Bering Sea was the second highest in the satellite record, paired with air temperatures that were 5 to 9 degrees  below average.

Filed under: climate and weather, Environment, global warming Tagged: | Arctic, Arctic sea ice extent, Barents Sea, Bering Sea, climate, Environment