NEWS: Around the Arctic August 15, 2012 - 9:20 am

Arctic sea ice continues to melt at record-breaking rates

A storm over the central Arctic Ocean coincides with rapid ice loss


People in the eastern regions of Canada’s Arctic wouldn’t have known it, but August saw a massive summer storm in the central Arctic Ocean which ice trackers believe contributed to massive ice loss there.

The average pace of sea ice loss since late June has been rapid at just over 100,000 square kilometres per day, said the Colorado-based National Snow and Ice Data Center on Aug. 13.

However, this pace nearly doubled for a few days in early August during a major Arctic storm.

A low pressure system entered the Arctic Ocean from the eastern Siberian coast on Aug. 4 and then strengthened rapidly over the central Arctic Ocean, the NSIDC said.

Low pressure systems over the Arctic Ocean generally tend to cause the ice to spread out and cover a larger area, and these storms often bring cool conditions and even snowfall, while high pressure systems over the Arctic cause the sea ice to converge.

But this month’s unusually strong storm produced high as well as low temperatures, and the sea ice extent dropped rapidly between Aug. 4 and Aug. 8.

“While this drop coincided with an intense storm over the central Arctic Ocean, it is unclear if the storm prompted the rapid ice loss,” the NSIDC said.

Meanwhile, Arctic sea ice extent during the first two weeks of August continued to track below 2007 record low daily ice extents.

As of Aug. 13, sea ice extent was already among the four lowest summer minimum extents in the satellite record, with about five weeks still remaining in the melt season.

Arctic sea ice extent on Aug. 13 was 4.90 million sq. km..

That’s 2.81 million sq km below the 1979 to 2000 average extent for the date, and 450,000 sq. km. below the previous record low for the date, recorded in 2007.

Ice is near its normal (1979 to 2000) extent only off the northeastern Greenland coast. The western entrance to the Northwest Passage via McClure Strait remains blocked, the NSIDC said.