Wintertime North American weather regimes and the Arctic stratospheric polar vortex

Lee, S. H., Furtado, J. C. and Charlton-Perez, A. J. ORCID: https://orcid.org/0000-0001-8179-6220 (2020) Wintertime North American weather regimes and the Arctic stratospheric polar vortex. Geophysical Research Letters, 46 (24). pp. 14892-14900. ISSN 0094-8276 doi: 10.1029/2019GL085592

Abstract/Summary

The impact of the Arctic stratospheric polar vortex on persistent weather regimes over North America is so far under-explored. Here we show the relationship between four wintertime North American weather regimes and the stratospheric vortex strength using reanalysis data. We find that the strength of the vortex significantly affects the behavior of the regimes. Whilst a regime associated with Greenland blocking is strongly favored following weak vortex events, it is not the primary regime associated with a widespread, elevated risk of extreme cold in North America. Instead, we find that the regime most strongly associated with widespread extremely cold weather does not show a strong dependency on the strength of the lower-stratospheric zonal-mean zonal winds. We also suggest that stratospheric vortex morphology may be particularly important for cold air outbreaks during this regime.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/87746
Identification Number/DOI	10.1029/2019GL085592
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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