New simulations showed changes in the jet stream are partially caused by sea ice losses in the Arctic sea ice. Photo by Stefan Hendricks/AWI
May 29 (UPI) -- New models suggest a warming Arctic is influencing the behavior of the jet stream and encouraging extreme weather events in the Northern Hemisphere, including cold spells in the winter and heatwaves in the summer.
Several scientists have previously suggested a link between Arctic warming and extreme weather, but climate scientists remain divided on the topic.
The latest research used a state-of-the-art climate model and a machine learning algorithm designed to understand ozone chemistry to simulate the behavior of the jet stream.
"We've developed a machine learning algorithm that allows us to represent the ozone layer as an interactive element in the model, and in so doing, to reflect the interactions from the stratosphere and ozone layer," Erik Romanowsky, an atmospheric researcher at the Alfred Wegener Institute, said in a news release.
The simulation showed that as the Arctic warms, the jet stream slows down and is less likely to take a straight path parallel to the equator. The updated climate model determined a combination of sea ice melting and atmospheric waves are helping warm the Arctic stratosphere, where the jet stream is located.
The Arctic's cool air is the jet stream's engine. As the Arctic stratosphere warms, jet stream winds peter out and the current slackens, forming waves. During the winter, the slack allows large masses of Arctic air to penetrate farther south, causing dangerous cold spells. In the summer, the greater amplitude waves allow warm air to move farther north. Without the mediating effects of cooler Arctic air, heatwaves can last for weeks across North America and Europe. Blocking of the jet stream also can cause strange weather patterns to linger for longer than usual.
Scientists published their findings this week in the journal Scientific Reports. The results of the paper echo the conclusions of previous studies, which predicted North American winters will be both warmer and colder in the future.
"After the successful use of machine learning in this study, we are now for the first time employing artificial intelligence in climate modeling, helping us arrive at more realistic climate model systems," climate scientist Markus Rex said. "This holds tremendous potential for future climate models, which we believe will deliver more reliable climate projections and therefore a more robust basis for political decision-making."