2021 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.