Long-Term Variations in Parameters of Sudden Stratospheric Warmings According to ERA5 Reanalysis Data

We present the long-term variations in the parameters of sudden stratospheric warmings (SSWs) from 1979 to 2021. The zonal mean air temperature at 80° N and zonal mean wind at 60° N at altitudes of 10 hPa are used as a criterion for the SSW estimation. Major and minor SSWs are classified into types, with the splitting of the polar vortex (PV) and with PV displacement. We estimated the variations in such SSW parameters as the number of events per winter, SSW type, SSW duration, onset date, and maximal temperature during SSW over the past 42 years. We found no trend-like changes, but rather the oscillation of these parameters in the high-latitude stratosphere.