Influence of the subtropical stratosphere on the Antarctic polar vortex during spring 2019

The stratospheric polar vortex strength in spring determines to a great extent the duration and intensity of ozone depletion in the polar regions. A temperature increase in the lower subtropical stratosphere in spring leads to an increase in the stratospheric equator-to-pole temperature gradient and the subsequent strengthening of the Antarctic polar vortex, accompanied by severe springtime ozone depletion. At the same time, the unusual weakening of the Antarctic polar vortex was observed in the spring of 2019. An abnormal temperature decrease in the lower subtropical stratosphere was recorded in the same time period and probably led to a decrease in the stratospheric equator-to-pole temperature gradient and the subsequent weakening of the polar vortex.