When it comes to sea ice in the Arctic, just call 2012 the year of the unknown. After a summer that saw the previous record low ice extent broken in August -- with a month still remaining in the melting season -- Arctic sea ice is on the rebound at a near-record pace.
October saw the levels of sea ice in the Arctic double, though after such a devastatingly bad melting season, it still left the average hovering around record low levels. That's according to the National Snow and Ice Data Center (NSIDC), which said that as of Sunday, the levels of ice in the Arctic had reached 3.17 million square miles. That's still about 200,000 square miles below the previous record low set in 2007, and more than 750,000 square miles below the 1979-2000 average.
The NSIDC reports Arctic ice in October grew at a rate of 46,700 square miles per day. That's thanks in part to a large Arctic air mass that has been impacting Alaska of late, where temperatures in many parts of the state remain stubbornly cold and clear. The Arctic air sweeping south even contributed to some of the power of superstorm Sandy, which struck the U.S. East Coast last week.
Speaking of Alaska, what about the state's Arctic waters, the Beaufort and Chukchi seas? The Beaufort suffered more during the summer melting season, while the Chukchi Sea remained among the more stubbornly icy waters in the Arctic. The Chukchi hovered around the historical average for much of the year, while the Beaufort saw greater loss than usual.
It would seem, though, that Arctic air is actually bypassing Alaska -- Barrow is one of the few locations in the state that's seen above-average temperatures recently. Sea ice in the Chukchi and Beaufort are recovering slowly, possibly due to similarly warm temperatures on Alaska's northern coast.
"While overall the Arctic rapidly gained ice throughout October, the rate of ice growth was not the same everywhere," the NSIDC reports. "Ice growth in the Beaufort and Chukchi seas averaged about 8,500 square kilometers (3,300 square miles) per day and large areas still remain ice free."
That compares with the eastern Arctic, which offset the Alaska Arctic's slow recovery with faster ice growth in the seas north of Russia.
In the end, October proved promising for sea-ice recovery after such a low year, though ice established during this winter until the melting season resumes in 2013 will be "new" ice, or ice that has been around for less than five years. New ice is more prone to the annual extreme freeze-thaw cycle that's become the new normal in the far north in recent years.
Contact Ben Anderson at ben(at)alaskadispatch.com