Recent decadal weakening of the summer Eurasian westerly jet attributable to anthropogenic aerosol emissions

Dong, B. ORCID: https://orcid.org/0000-0003-0809-7911, Sutton, R. T. ORCID: https://orcid.org/0000-0001-8345-8583, Shaffrey, L. ORCID: https://orcid.org/0000-0003-2696-752X and Harvey, B. ORCID: https://orcid.org/0000-0002-6510-8181 (2022) Recent decadal weakening of the summer Eurasian westerly jet attributable to anthropogenic aerosol emissions. Nature Communications, 13. 1148. ISSN 2041-1723 doi: 10.1038/s41467-022-28816-5

Abstract/Summary

The Eurasian subtropical westerly jet (ESWJ) is a major feature of the summertime atmospheric circulation in the Northern Hemisphere. Here, we demonstrate a robust weakening trend in the summer ESWJ over the last four decades, linked to significant impacts on extreme weather. Analysis of climate model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) suggests that anthropogenic aerosols were likely the primary driver of the weakening ESWJ. Warming over mid-high latitudes due to aerosol reductions in Europe, and cooling in the tropics and subtropics due to aerosol increases over South and East Asia acted to reduce the meridional temperature gradient at the surface and in the lower and middle troposphere, leading to reduced vertical shear of the zonal wind and a weaker ESWJ in the upper troposphere. If, as expected, Asian anthropogenic aerosol precursor emissions decline in future, our results imply a renewed strengthening of the summer ESWJ.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/103947
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Nature Publishing Group
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