Arctic warming is stalling the movement of weather fronts
Summer weather is “stalling” due to Arctic warming
Rising arctic temperatures mean we face a future of ‘extreme extremes’ where sunny days become heatwaves and rain becomes floods, study says
The Guardian (U.K.), Aug. 20, 2018
Summer weather patterns are increasingly likely to stall in Europe, North America and parts of Asia, according to a new climate study that explains why Arctic warming is making heatwaves elsewhere more persistent and dangerous.
Rising temperatures in the Arctic have slowed the circulation of the jet stream and other giant planetary winds, says the paper, which means high and low pressure fronts are getting stuck and weather is less able to moderate itself.
The authors of the research, published in Nature Communications on Monday, warn this could lead to “very extreme extremes”, which occur when abnormally high temperatures linger for an unusually prolonged period, turning sunny days into heat waves, tinder-dry conditions into wildfires, and rains into floods.
“This summer was where we saw a very strong intensity of heatwaves. It’ll continue and that’s very worrying, especially in the mid-latitudes: the EU, US, Russia and China,” said one of the coauthors, Dim Coumou from the Potsdam Institute for Climate Impact Research. “Short-term heatwaves are quite pleasant, but longer term they will have an impact on society. It’ll have an effect on agricultural production. Harvests are already down this year for many products. Heatwaves can also have a devastating impact on human health.”
Circulation stalling has long been a concern of climate scientists, though most previous studies have looked at winter patterns. The new paper reviews research on summer trends, where it says there is mounting evidence of planetary wind systems – both low-level storm tracks and higher waves in the troposphere – losing their ability to shift the weather.