Jet Stream Winds Will Accelerate With Warming Climate

By ucar.edu

New research by the University of Chicago and the U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR) finds that fast jet stream winds will get significantly faster by mid century because of climate change.

The study, in Nature Climate Change, suggests that the fastest upper-level jet stream winds will accelerate by about 2% for every degree Celsius (1.8° Fahrenheit) that the world warms. Furthermore, the fastest winds will speed up 2.5 times faster than the average wind.

Jet stream winds are powerful and narrow bands in the upper atmosphere that generally move from west to east, influencing weather patterns as well as aircraft. Faster winds would likely increase the potential for severe weather, and they could worsen clear air turbulence for air travelers while affecting flight times.

Jet streams form because of the contrast between the cold, dense air at the poles and the warm, light air in the tropics, in combination with the rotation of the Earth. The new study, by University of Chicago Professor Tiffany Shaw and NSF NCAR scientist Osamu Miyawaki, uses climate models to show that climate change intensifies this density contrast because moisture levels for air above the tropics will increase more than above the poles.

“This may have implications for air travel,” Miyawaki said. “The faster the jet stream winds, the more severe the impacts on turbulence. The faster winds may also lead to conditions that are favorable for stronger and more prolonged storms.”

He added that higher-resolution computer models are needed to fully understand the potential impacts on turbulence.