Since shrinking at a torrid pace in the first half of July, the Arctic sea ice meltdown has slowed markedly.
“I’ve seen slowdowns before, but this is out of this world,” writes the Arctic Sea Ice blog.
The blog notes Arctic sea ice actually expanded by 20,000 square kilometers for 10 days at the end of July.
“That’s so crazy for this phase of the melting season that I barely have words for it,” the blog says. “It’s unique as far as the record goes.”
The National Snow and Ice Data Center (NSIDC) says storminess in the second half of July likely halted the rapid retreat of ice that took place in the early part of the month.
“[A stormy pattern] brought more counterclockwise winds and cool conditions, and spread the ice out,” NSIDC writes.
The storminess of late July has continued into early August. A large storm has consumed a vast section of the Arctic this week.
“I just spotted what appears to be a massive cyclone — bigger than all of Greenland — in [Wednesday’s] daily Arctic mosaic from NASA’s Terra satellite,” writes Tom Yulsman at his ImageGeo blog at Discover.
The Arctic Sea Ice blog notes this is the third major storm of the melt season in the region.
Will this storm act to apply additional brakes on Arctic melting?
NSIDC says not necessarily. Although storms can help spread out ice and increase its extent (in the past, stormy summers have usually had greater ice extents), storms may leave it vulnerable for a rapid meltdown once calmer, sunnier weather moves in, especially if the ice is thin.
“This spreading of the ice, or ice divergence, can result in more dark open water areas between individual floes that enhance absorption of the sun’s energy, leading to more lateral and basal melting,” writes NSIDC.
Because of the long term decline in ice thickness and volume in the Arctic, much of the ice that storms have been moving around is fragile, thin first-year ice (rather than the thicker multi-year ice which would be around but for the well-documented long-term decline). As such, it’s not out of the question rapid ice loss could resume, given the right weather conditions.
In 2012, Arctic sea ice shrunk to its lowest extent on record in the weeks following a very powerful August storm.
“It appears that the August 2012 storm was attended by a modest acceleration in the pace of summer ice loss,” NSIDC writes.
But even if melting resumes in earnest this year, the Arctic Sea Ice blog has ruled out a new record for low extent in 2013…simply due to the amount of ground to make-up (or, in reality, lose).
“There’s still 5-6 weeks to go until the end of the melting season, but 2013 is trailing 2012 by over 1.2 million square kilometers,” the blog writes. “A new record has become impossible for all practical purposes.”