Super-hot Arctic has scientists worried

WASHINGTON • Political people in the United States are watching the chaos in Washington at the moment. But some people in the science community are watching the chaos somewhere else - the Arctic.

It is polar night there now. That is when the Arctic is supposed to get super-cold, when the sea ice that covers the vast Arctic Ocean is supposed to grow and thicken.

But in fall 2016 - which has been a zany year for the region, with multiple records set for low levels of monthly sea ice - something is totally off. The Arctic is super-hot, even as a vast area of cold polar air has been displaced over Siberia.

At the same time, one of the key indicators of the state of the Arctic - the extent of sea ice covering the polar ocean - is at a record low right now. The ice is freezing up again, as it always does this time of year after reaching its September low, but it is not doing so as rapidly as usual.

Not only are air temperatures unusually warm, but water temperatures are as well.

Dr Mark Serreze, who heads the National Snow and Ice Data Centre in Colorado, said: "There are some areas in the Arctic Ocean that are as much as 25 deg F (13.9 deg C) above average now. It's pretty crazy."

What is happening, he said, is sort of a "double whammy".

On the one hand, there is a "very warm underlying ocean" due to the lack of sea ice forming above it. But, at the same time, kinks in the jet stream have allowed warm air to flow northward and frigid Arctic air to descend over Siberia.

The development is worrying because sea ice in the Arctic and Antarctic reflects large amounts of sunlight back into space. Melting ice means much of that heat is instead absorbed by the much darker ocean, heating up the sea and in turn melting more ice.

WASHINGTON POST

A version of this article appeared in the print edition of The Sunday Times on November 20, 2016, with the headline 'Super-hot Arctic has scientists worried'. Print Edition | Subscribe