The American Geophysical Union documents a significant rift in the Last Ice Area just north of Ellesmere Island in the Canadian arctic in May of 2020. A hole of open water in sea ice is known as a polynya, and its formation is remarkable because the ice in the area is up to five meters thick. The culprit, they discovered, was the wind. A polynya had never been observed in the area before.
"No one had seen a polynya in this area before. North of Ellesmere Island it's hard to move the ice around or melt it just because it's thick, and there's quite a bit of it. So, we generally haven't seen polynyas form in that region before," said Kent Moore, an Arctic researcher at the University of Toronto-Mississauga who was lead author on the study.
The surprise polynya formed during extreme wind conditions in a lingering anti-cyclone, or a high-pressure storm with high winds that rotate clockwise, Moore found. He combed through decades of sea-ice imagery and atmospheric data and found that polynyas formed there at least twice before, under similar conditions in 2004 and 1988, but no one had noticed.
With Arctic ice getting thinner every year, polynyas could form more frequently, setting off a feedback loop of ice loss.
"The thing about thinning ice is that it's easier to move it around. As the ice gets thinner, it's easier to create these polynyas with less extreme forcing, so there is some evidence that these polynyas may become more common, or become larger, than they were in the past," Moore said. And warmer temperatures mean that lost ice is not likely to be replaced.
I keep vigil.