Arctic sea ice extent down, thickness up: data center

This map shows sea ice thickness in meters in the Arctic Ocean from March 29 to April 25. (IMAGE COURTESY OF THE CENTER FOR POLAR OBSERVATION AND MODELLING)

Arctic sea ice extent averaged for April was smaller in size, but thicker.

That’s according to the Colorado-based National Snow and Ice Data Center, which has been tracking ice with satellites since 1981.

Arctic sea ice extent for the month averaged 14 million square kilometres, the second lowest April ice extent in the satellite record.

But it was thicker than in previous years, particularly off Greenland and around Canada’s Arctic islands, where temperatures were one to three degrees C below average, the NSIDC said May 6.

Arctic sea ice thickness in the spring of 2015 came in at about 25 centimetres thicker than in 2013, with ice more than 3.5 m (11.5 feet) thick is found off the coast of Greenland and in Canada’s Arctic islands.

Recent research still points to an irreversible long time trend in the decline in the thickness of Arctic sea ice, with even several cold years in the Arctic are unlikely to change the downward trend in thickness.

April was still marked by rapid sea ice loss at the beginning and end of the month, with air temperatures remaining higher than average, one to three C higher, over much of the Arctic Ocean, the NSIDC said.

And there was “a fairly rapid decline during the first week of the month, little change during the middle of the month, and then a steep decline over the final week,” the NSDIC said.

Overall, sea ice extent decreased by 862,000 sq. km., the area of second-year ice decreased by more than a third during the winter and ice of four years and more declined by about 10 per cent.

This year’s maximum Arctic sea ice extent occurred early in March — and it was also the lowest level recorded in the satellite record.