It’s hot. Blame it on the jet stream
Sweltering? Choking on bushfire smoke? Blame it on the jet stream.
The ribbon of wind that circles the Earth is doing strange things. The calamity list includes fires in Scandinavia, Greece, California and record heat in Texas, Japan, Africa.
“We are seeing some extreme jetstream behaviour, where the jet stream is contorting into these extreme loops both sharply towards the poles with ridges of high pressure and dips to the equator with troughs of low pressure,” said Jeff Masters, cofounder of Weather Underground. “The extreme configuration is getting stuck in place which means that places are getting long periods of extreme weather.”
Globally, at least 170 people have died in fires, floods and heat on three continents. Temperature records were shattered in Japan when readings reached 41C. Waco, Texas, hit an all-time high of 45C. The situation in Scandinavia has been “pretty mind boggling,” with the Baltic Sea water rising to well above average and Lapland north of the Arctic Circle reaching the 30s.
Earlier in July, Ouargla, Algeria hit 51.2C, which is the highest temperature recorded in Africa, said Kevin Trenberth of the National Centre for Atmospheric Research. “In very arid conditions, those sort of things are possible and we are seeing more of them in different places.”
Science will need time to study if this extra-hot summer is because of climate change, but this is what global warming would look like. The cause of why the blocking in the atmosphere started this July might require a bit of study too, said Greg Carbin of the US Weather Prediction Centre.
There’s a large high-pressure system spinning clockwise in the western Atlantic Ocean, dominating the basin and leaving weather patterns backed up . There is a trough over the Bering Sea, a deep area of low pressure, that is helping keep the US Southwest hot.
“Any heat wave has both natural and now, human causes,” said Michael Wehner of Lawrence Berkeley National Laboratory. “Climate change simply makes these heat waves hotter than they would have been otherwise.”