After 2012 saw record-shattering sea ice melt in the Arctic during the summer months, 2013 is highly unlikely to repeat the feat, NASA reported Friday. With cooler temperatures expected to the return to the world's most northerly latitudes and re-freezing set to begin in the coming weeks, this summer will likely go down as just one in a trend of lesser-ice years, but not the one with the least.
The extent of Arctic sea ice stretched a mere 1.3-million square miles when refreezing began on Sept. 16, 2012, breaking the previous record low by more than a quarter-million square miles. By Aug. 27 last year, the old record -- set in 2007 -- had already been surpassed.
This summer has fared significantly better though, as NASA reports that 2013 is unlikely to see a new record. Aug. 21 saw an ice extent of 2.25 million square miles, compared with 1.67 million square miles on the same day last year.
It does, however, continue a trend of overall downward extent that bodes ill for the future of Arctic sea ice -- and the animals and ecosystems that depend on it. Even this year's ice extent on Aug. 21 paled in comparison to 1996, when sea ice covered the span of a whopping 3.16 million square miles.
“Even if this year ends up being the sixth- or seventh-lowest extent (on record), what matters is that the 10 lowest extents recorded have happened during the last 10 years,” said Walt Meier, a glaciologist with NASA’s Goddard Space Flight Center. “The long-term trend is strongly downward.”
Meanwhile, NASA release this computer animation of sea ice lost thus far in 2013:
The National Snow and Ice Data Center in Colorado affirmed NASA's prediction that 2013 wasn't as bad as last year.
"Arctic sea ice extent maintained a steady, near-average pace of retreat through the first half of August, making it highly unlikely that a new record low minimum will be reached this year," the NSIDC reported.
Both the NSIDC and NASA said that a particularly vicious "Arctic cyclone" contributed to the late-season loss of ice in 2012 and adding to the already faster-than-normal loss of ice.
"Last year’s storm went across an area of open water and mixed the smaller pieces of ice with the relatively warm water, so it melted very rapidly,” Meier said. “This year, the storms hit in an area of more consolidated ice. The storms this year were more typical summer storms; last year’s was the unusual one.”
Additionally, the continued lows of sea ice in recent years has led to thinning ice pack, increasing open water leads in the Arctic and contributing to the formation of polynyas, sections of open water surrounded by ice.
One region where sea ice has been particularly stubborn is in Alaska's Beaufort and Chukchi seas -- extending even down through the Bering Strait -- though the NSIDC reported that those exceptions to the receding-ice rule were beginning to fade faster as the melting season has worn on.
"Retreat rates increased slightly in the western Beaufort Sea and Chukchi Sea, but ice cover remains extensive in those regions compared to 2012," the NSIDC said.
Freezing typically begins anytime between early and late-September, with the average in mid-September. The NSIDC said it anticipates this year's low extent will hover somewhere around 2 million square miles.
Contact Ben Anderson at ben(at)alaskadispatch.com