Long-term variability of parameters of sudden stratospheric warmings according to ERA5 reanalysis data
O.S. Zorkal’tseva1, O.Yu. Antokhina2, P.N. Antokhin2
1Institute of Solar-Terrestrial Physics of the Siberian Branch of the RAS, Irkutsk, Russia
2V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: sudden stratospheric warming, stratosphere, methods for identifying stratospheric warmings
Abstract
This paper is devoted to assessing the long-term variability of the parameters of sudden stratospheric warmings (SSW) from 1979 to 2021. The values of the mean zonal air temperature at a latitude of 80°N and zonal average wind speed at 60°N at altitudes of 10 hPa are used as a criterion for estimating the SSW. Major SSWs are classified according to their types - with split of the polar vortex (PW) and with PW displacement. Estimates are made of the variability of such SSW parameters as the number of events per winter, SSW type, SSW duration, start date and maximal temperature during SSW over the past 42 years. No trend changes are found, but oscillatory behavior of the parameters is observed in the high-latitude stratosphere.
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