Wednesday, July 28

Arctic Warming May Be To Blame For Texas Snowstorms, Scientists Argue | Sciences


Sign up for The Guardian’s Green Light newsletter

Associating climate change, usually related to scorching heat, with an unusual winter storm that has paralyzed swaths of Texas and caused freezing temperatures in the southern United States may seem counterintuitive. But scientists say there is evidence that the rapid warming of the Arctic may help push icy air from the north pole much further south, possibly toward the US-Mexico border.

This week, a flurry of winter weather has penetrated deep into the heart of the US, causing several deaths and leaving an estimated 5 million people without power. Sleet and ice have hit Oklahoma and Arkansas, while many people in Texas have been stranded, amid unsafe travel conditions, in homes without electricity.

“Current conditions in Texas are historic, certainly generational,” said Judah Cohen, director of seasonal forecasting for Atmospheric and environmental research. But this cannot be dismissed as completely natural. This is happening not despite climate change, it is due in part to climate change ”.

Last year, Cohen co-authored an article which found a strong spike in winter storms in the northeastern US in the decade leading up to 2018. This, Cohen and some other scientists argue, is a symptom of warming in the Arctic, occurring at a slower rate. twice the world average, which is disrupting long-established climate systems.

Cold air normally concentrates around the north pole in the polar vortex, an area of ​​low pressure that circulates in a tight formation in the stratosphere during winter. Scientists liken this rotation to a spinning top, one that can meander if interfered with.

This interference, the researchers say, occurs through changes in the jet stream, a band of strong winds that engulfs the world at elevations lower than the polar vortex. The warming Arctic is believed to be causing the jet stream to change. “The energy escaping from the jet stream hits the polar vortex, so it starts to wobble and move around,” Cohen said. “Where the polar vortex goes, so does the cold air.”

This phenomenon has been shown to a dramatic degree over the past month, with a polar vortex splitting helping to cause huge flurries of snow in Europe, as well as record cold temperatures in parts of the US more used to milder winters. .

“I would say that the situation this winter is consistent with research that has connected what is happening in the Arctic with extreme weather patterns in the middle latitudes,” said Jennifer Francis, a senior scientist at the Woodwell Climate Research Center who has studied the subject. “The polar vortex can elongate, spread out in different ways, and even split. We have seen a huge disruption this year. “

There is no consensus among scientists on the interaction between Arctic heat and cold climate further south; Francis calls the topic an “active area of ​​investigation.” Global warming is causing warmer winters and record cold temperatures are now being recorded. clearly outmatched by record temperatures, but the complex interplay of weather conditions still requires greater scrutiny, to the dismay of some and even mockery among others, including former US presidents..

“We still have a lot to learn about this,” Francis said. “I think this year will be studied for a long time.”




www.theguardian.com

Leave a Reply

Your email address will not be published. Required fields are marked *