Dynamical evolution of a minor sudden stratospheric warming in the Southern Hemisphere in 2019

• Published in: Atmospheric chemistry and physics Vol. 22; no. 5; pp. 3493 - 3505
• Main Authors: Liu, Guangyu, Hirooka, Toshihiko, Eguchi, Nawo, Krüger, Kirstin
• Format: Journal Article
• Language: English; Norwegian
• Published: Katlenburg-Lindau Copernicus GmbH 16.03.2022; Copernicus Publications
• Subjects: Analysis; Atmospheric circulation; Deceleration; Easterlies; Lower stratosphere; Planetary waves; Polar caps; Polar vortex; Preconditioning; Propagation; Refractive index; Refractivity; Rossby waves; Southern Hemisphere; Stationary planetary waves; Stratosphere; Stratospheric warming; Temperature; Temperature rise; Traveling waves; Upper stratosphere; Vortices; Wave propagation; Waveguides; Wavelengths; Waves; Westerlies; Wind; Winds; Zonal flow; Zonal flow (meteorology); South Pole; Southern Hemisphere
• ISSN: 1680-7324; 1680-7316; 1680-7324
• DOI: 10.5194/acp-22-3493-2022

A major strong sudden stratospheric warming (SSW) occurred in the Southern Hemisphere (SH) stratosphere in 2002 (hereafter referred to as SSW2002), which is one of the most unusual winters in the SH. Following several warmings, the polar vortex broke down in midwinter. Eastward-traveling waves and their interaction with quasi-stationary planetary waves played an important role during this event. This study analyzed the Japanese 55-year reanalysis (JRA-55) dataset to examine the SSW event that occurred in the SH in 2019 (hereafter referred to as SSW2019). In 2019, a rapid temperature increase and decelerated westerly winds were observed at the polar cap, but since there was no reversal of westerly winds to easterly winds at 60.sup." S in the middle to lower stratosphere, the SSW2019 was classified as a minor warming event.