Throughout the month of August, Arctic sea ice extent tracked below levels observed in 2007, leading to a new record low for the month of 4.72 million square kilometers (1.82 million square miles), as assessed over the period of satellite observations,1979 to present. Extent was unusually low for all sectors of the Arctic, except the East Greenland Sea where the ice edge remained near its normal position. On August 26, the 5-day running average for ice extent dropped below the previous record low daily extent, observed on September 18, 2007, of 4.17 million square kilometers (1.61 million square miles). By the end of the month, daily extent had dropped below 4.00 million square kilometers (1.54 million square miles). Typically, the melt season ends around the second week in September.
From the Christian Science Monitor (Pete Spotts):
As of Sept. 7, the Arctic Ocean’s expanse of summer ice this month spanned less than 1.54 million square miles, nearly six times the size of Texas and some 45 percent less than for the average for the same month through the 1980s and ’90s, according to the National Snow and Ice Data Center in Boulder, Colo. And the ice is still retreating; the summer melt season typically ends in mid to late September.
The previous record low was set in 2007, a result of an unusual set of conditions – clear skies during most of the summer and wind patterns that drove large amounts of ice past Greenland and into the North Atlantic. This summer, no such “perfect storm” for ice loss appeared.
Instead, much of the ice left over from winter – coming out of a summer that until now had been the second lowest melt-back in the satellite record – was thin enough to break no matter which way the wind blew, according to NSIDC researchers.