Extreme cold winters fuelled by jet stream and climate change

October 26, 2016, University of Sheffield
Credit: Larisa Koshkina/public domain

The research, carried out by an international team of scientists including the University of Sheffield, has found that warming in the Arctic may be intensifying the effects of the jet stream's position, which in the winter can cause extreme cold weather, such as the winter of 2014/15 which saw record snowfall levels in New York.

Scientists previously had two schools of thought. One group believe that natural variability in the jet stream's position has caused the recent severe cold winter weather seen in places such as the Eastern United States and the UK. The other camp includes scientists who are finding possible connections between the warming of the Arctic – such as melting sea ice, warming air temperatures, and rising sea surface temperatures – and the emerging pattern of severe cold winter weather.

Now, Professor Edward Hanna and Dr Richard Hall from the University's Department of Geography, together with Professor. James E. Overland from the US Oceanographic and Atmospheric Administration (NOAA), have brought together a diverse group of researchers from both sides of the debate.

The researchers have found that the recent pattern of cold winters is primarily caused by natural changes to the jet stream's position; however, the warming of the Arctic appears to be exerting an influence on cold spells, but the location of these can vary from year to year.

Previous studies have shown that when the jet stream is wavy there are more episodes of severe cold weather plunging south from the Arctic into the mid-latitudes, which persist for weeks at a time. But when the jet stream is flowing strongly from west to east and not very wavy, we tend to see more normal winter weather in countries within the mid-latitudes.

 "We've always had years with wavy and not so wavy , but in the last one to two decades the warming Arctic could well have been amplifying the effects of the wavy patterns," Professor Hanna said. He added: "This may have contributed to some recent extreme cold winter spells along the eastern seaboard of the United States, in eastern Asia, and at times over the UK (e.g. 2009/10 and 2010/11).

"Improving our ability to predict how climate change is affecting the jet stream will help to improve our long-term prediction of winter weather in some of the most highly populated regions of the world.

"This would be hugely beneficial for communities, businesses, and entire economies in the northern hemisphere. The public could better prepare for severe and have access to extra crucial information that could help make live-saving and cost-saving decisions."

Explore further: New evidence links Arctic warming with severe weather

More information: James E. Overland et al. Nonlinear response of mid-latitude weather to the changing Arctic, Nature Climate Change (2016). DOI: 10.1038/nclimate3121

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6 comments

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SamB
1 / 5 (4) Oct 26, 2016
And just wait until a new ice age kicks in. Then you will see how "wavy the patterns" get...
antigoracle
1 / 5 (4) Oct 26, 2016
Perhaps they can explain where the manmade Globull warming came from to cause the extreme winters during the 1940s...oh...wait...that does not fit the AGW Cult's agenda.
tblakely1357
1 / 5 (3) Oct 27, 2016
Too hot - Global Warming
Too cold - Global Warming
Too wet - Global Warming
Too dry - Global Warming

Is there anything it can't do?
hanterp
not rated yet Oct 27, 2016
Too hot - Global Warming
Too cold - Global Warming
Too wet - Global Warming
Too dry - Global Warming

Is there anything it can't do?

Yes, true, global warming can have many effects ;-)
Here in Holland we only have wetter and warmer effects. We did not have snow the last few years, very warm winters and in the summer we got extreme warm weather. We even got some days in the 30 degrees celsius in september! That was a record for september!
optical
Oct 27, 2016
This comment has been removed by a moderator.
optical
Oct 27, 2016
This comment has been removed by a moderator.

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