Antarctic Ozone Hole [in ”State of the Climate in 2021”]

The 2021 Antarctic ozone hole was the 13th largest in 42 years of satellite observations since
1979, with an area of 23.34 × 106 km2 (the average area for 7 September–13 October) and a minimum
daily total ozone column of 92 DU. The 2021 polar stratospheric vortex was stable with
consistently cold temperatures that created favorable conditions for ozone depletion. The meteorological
conditions and seasonal development of the ozone hole in 2021 were similar to those in
2020. Weaker-than-usual amplitudes of planetary scale Rossby waves in the September–October
period helped maintain a strong vortex and led to below-average Antarctic ozone columns in late
austral spring and early summer.