Wondering why North America is having unseasonably cold and snowy weather?
Chris Mooney, Sydney Morning Herald
November 22, 2014
It may be the timeliest - and most troubling - idea in climate science.
Back in 2012, two researchers with a particular interest in the Arctic, Rutgers' Jennifer Francis and the University of Wisconsin-Madison's Stephen Vavrus, published a paper called "Evidence linking Arctic amplification to extreme weather in mid-latitudes." In it, they suggested that the fact that the Arctic is warming so rapidly is leading to an unexpected but profound effect on the weather where the vast majority of Americans live - a change that, if their theory is correct, may have something to do with the extreme winter weather the US has seen lately.
In their paper, Francis and Vavrus suggested that a rapidly warming Arctic should interfere with the jet stream, the river of air high above us that flows eastward around the northern hemisphere and brings with it our weather. Sometimes, the jet stream flows relatively directly from west to east; but other times, it takes long, wavy loops, as in the image above. And according to Francis and Vavrus, Arctic warming should make the jet stream more wavy and loopy on average – some have called it "drunk" - with dramatic weather consequences.
(Read more here.)