Antarctic Polar Vortex Dynamics Depending on Wind Speed Along the Vortex Edge

The stratospheric polar vortices play a key role in springtime polar ozone depletion and can influence the stratospheric circulation. In this work, we use the method of vortex delineation based on geopotential values determined from the maximum temperature gradient and maximum wind speed, thus characterizing the edge of the Antarctic polar vortex. Using the vortex delineation method based on the ERA5 reanalysis data for 1979–2019, we characterized the dynamics of the Antarctic polar vortex in the lower stratosphere depending on the prevailing wind speed along the vortex edge. We filtered out cases of weakening of the dynamic barrier, which prevents the penetration of air masses into the polar vortex. We show that in the lower stratosphere the area of the Antarctic polar vortex usually exceeds 10 million km2, the mean wind speed along the vortex edge typically exceeds 30 m/s, and the mean temperature inside the vortex is in most cases less than −50 °C.