Another record low for Arctic ice extent

Following a record low in December, the Arctic sea ice extent hit the record books again in January, the National Snow and Ice Data Center reported Feb. 2. At 5.23 million square miles the average January sea ice extent fell 19,300 square miles below the previous January record, set in 2006, and 490,000 square miles below the 1979 to 2000 January average (satellite ice observations began in 1979).

Ice cover was especially low in Hudson Bay; Hudson Strait, between southern Baffin Island and Labrador; and Davis Strait, between Baffin Island and Greenland; with Hudson Bay not completely freezing over until mid-January — usually the sea in the Hudson Bay region freezes over by late November, NSIDC said. The shortage of ice reflected higher than average temperatures over much of the Arctic, with January temperatures 2 F to 6 F higher than normal over much of the region, and temperatures at least 6 F higher than normal over the Canadian Arctic Archipelago, Baffin Bay, the Davis Strait and the Labrador Sea. Temperatures were more normal over the western Arctic Archipelago and Scandinavia, NSIDC said.

NSIDC attributes the high temperatures to the release of heat from unfrozen areas of ocean and to an unusual wind pattern resulting from higher than normal Arctic atmospheric pressure. Conversely, the higher than usual air pressure, known as a negative Arctic oscillation, has caused abnormally cold winter weather in northern Europe and down the East Coast of North America.

Scientists are investigating possible linkages between more frequent episodes of a negative Arctic oscillation and overall Arctic sea ice losses, and the relationships between these phenomena and early snowfall in northern Siberia, NSIDC said.

—Alan Bailey