LONDON—Warming in the Arctic—one of the fastest-warming regions on the planet—could be heightening the chances of extreme winters in Europe and the US.
As the Arctic warms, the stratospheric jet stream that brings occasionally catastrophic ice storms and record snow falls to the eastern United States could also be on the move, according to new research in the journal Nature Climate Change.
The phenomenon is a natural one. Some years the track of the jet stream is wavy, and delivers severe cold weather to the mid-latitudes of the northern hemisphere. Some years the pattern alters, and Europe in particular experiences mild winters. The temperate zones have always experienced occasional extremes. But climate change could be tilting the balance.
“We’ve always had years with wavy and not so wavy jet-stream winds, but in the last one or two decades the warming Arctic could well have been amplifying the effects of the wavy patterns.
“This may have contributed to some recent extreme cold winter spells along the eastern seaboard of the United States, in western Asia and at times over the UK,” says Edward Hanna, a geographer at the University of Sheffield, UK, and one of a team of British, European and US scientists behind the study.