Andrew Revkin points to the uncertainty about what this means for Arctic sea ice, but to me the expert William Chapman at the Arctic Sea Ice Blog sounds a different note -- this major breakup of sea ice is unprecedented.
That large patch of sea ice in the East Siberian Sea is almost entirely detached from the main ice pack. This is something I for one have never seen before, and I wouldn't be surprised if it's unprecedented in the satellite era. We have speculated a lot about this in previous melting seasons, but now the moment seems to have finally arrived. The fact that the ice pack can get divided like this, is yet another sign that the ice is exceptionally thin, as thin ice gets pushed around more easily and melts quicker, leaving open space between thicker, slower moving ice floes.
Not easy for a novice to see what he's talking about in the picture. Revkin talks to Chapman, an Arctic expert with whom he has traveled to the frozen north, and Chapman speaks of the strangeness of this storm -- but does suggest these sort of polar lows are more likely on a warming planet.
This storm is intense for any time of year, but especially for summer, when the weather is normally fairly benign in the Arctic. This storm formed and intensified near the Beaufort Sea and moved to the central Arctic Ocean where it will slowly lose its intensity over the next several days. Ordinarily, the Beaufort Sea and the Arctic Ocean are dominated by high pressure, so having a low pressure system form and intensify here is quite uncommon. Although, it has been happening with more frequency over the past few decades as pressures have dropped significantly in the Arctic during this time and are projected to drop even more during the next century by the global climate models.
This is only the eighth such storm in the last 34 years in August in the Arctic. They're calling it The Great Arctic Cyclone of 2012.