When you read the piece below, you'll see the following quote by Serreze: "People seem to have this thought that all this storminess is unusual." He might be referring to my posts on the subject. Although I never said it is unusual (and wrote a long piece that put the persistence of the long-lasting cyclone in perpective), I wonder if we were seeing something new after last year's Great Arctic Cyclone. That's just something I tend to do given the rapid changes in the Arctic, compounded by the fact that I did see storms in the Arctic since starting the blog, but not three in one melting season.
In the end I'm mostly interested in the effect they have on the ice pack. In contrast to last year's late monster cyclone, they seem to have preserved the ice this year.
Here's the Icelights piece:
Are Arctic cyclones chewing up sea ice?
The Great Arctic Cyclone of 2012 lifted out of Siberia on August 2nd, swirling in a counter-clockwise rotation up into the Arctic. As one of the most extreme Arctic cyclones ever recorded, its consumption of an already low sea ice extent raised many concerns. Now Arctic cyclones are garnering attention, but is all the hype warranted?
“People seem to have this thought that all this storminess is unusual,” said Mark Serreze, an Arctic climatologist and center director at NSIDC. “Well it’s not. It simply isn’t. Summer is the time for cyclones.” Arctic summers are not calm. In fact, the months of August and September see a maximum amount of cyclonic activity. Not every summer is very stormy, but overall, the Arctic is the Arctic for a reason.
How much did the Great Arctic Cyclone of 2012 contribute to ice loss? Less than 5 percent, according to a study led by Jinlun Zhang and published in Geophysical Research Letters. The scientists point out that 2012′s record loss was 18 percent greater than the previous low, set in 2007, meaning the record low was going to get there with or without the big one.
The rise of cyclones
Adding to confusion of the Arctic’s storminess, the Atlantic side can be calm in the summer. But this isn’t the area being discussed in terms of cyclone activity. In the Northern Beaufort Sea, north of Alaska, summer is tempestuous. “The reason we have storms in the first place is that they do a job—transferring heat and momentum poleward,” Serreze said. In the Northern Hemisphere, winters are stormier because of the temperature gradient between the Arctic, which is dark and cold, and the equatorial regions, which are sunny and warm. “But embedded within that overall pattern, what happens on a regional basis can be quite different,” Serreze said.
During an Arctic summer, temperature gradients develop between the Arctic Ocean and the snow-free land, forming the Arctic frontal zone, where the land heats up strongly in contrast to the ocean along the coast. Most cyclones generate along this frontal zone and then migrate into the central Arctic Ocean.
Are the storms getting stronger? “No,” Serreze said. “Most of the evidence is actually showing that the frequency of stormy months is decreasing, favoring fair weather conditions. It’s not clear why, but it’s what’s been observed lately.”
Read the rest here.