Aerosols Have an Outsized Impact on Extreme Weather

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Scientists at Caltech and JPL have tied a shift in winter weather patterns in Europe and northern Eurasia to a reduction in air pollution.

Scientists at Caltech and JPL have tied a shift in winter weather patterns in Europe and northern Eurasia to a reduction in air pollution.

Over the past 50 years, the occurrence of extremely cold days has decreased throughout Europe and northern Eurasia, which includes Russia. Combining long-term observations with a state-of-the-art climate model revealed what researchers describe as an "unambiguous signature" of the reduction in the release of man-made aerosols over that time. This has caused changes in the wintertime Northern Hemisphere polar jet stream (a swiftly moving channel of air flowing from west to east) and surface-temperature variability during that time.

The work suggests that aerosols, which are solid particles polluting the atmosphere from activities like burning coal, can have a stronger impact on extreme winter weather than greenhouse gases at regional scale, although the relationship between aerosols and extreme weather is complicated to untangle.

"This discovery underscores the importance of understanding the effects of anthropogenic aerosols for accurate climate projection of extreme weather events, which is crucial to formulating climate mitigation and adaption strategies," says Yuan Wang, staff scientist at Caltech and at JPL, which Caltech manages for NASA, and the lead author of a study about the research that was published in Nature Climate Change on February 3.

Read more at California Institute of Technology

Image by Robert Marinkovic from Pixabay