Antarctic total ozone longitude–latitude dependence on sudden stratospheric warmings

We use Multi-Sensor Reanalysis and ground-based total ozone content (TOC) data to study total ozone variations in Antarctica near the dates of sudden stratospheric warmings (SSW). Three events were analyzed, including the warmings in 1988, 2002 (major warming), and 2019. All of them occurred in September, during the period of ozone hole development. Total ozone over stations with different latitudes and longitudes was considered to understand the properties of its variations in different parts of the stratospheric polar vortex and over the surrounding area. The 1979–2022 TOC climatology was obtained from the Multi-Sensor Reanalysis data. The multi-year mean shows a main total ozone minimum in September–October with values lower than 200 Dobson Units (DU) in the Atlantic longitudinal sector (Rothera, Faraday/Vernadsky). The annual TOC maximum of 280–300 DU occurs at the Antarctic stations, mainly in December. The exception is Dumont-d’Urville, located in the zonal maximum region and characterized by higher ozone levels of about 340 DU, which are reached in October–November. Composite analysis is carried out to study the interrelation between SSW events and total ozone variations. We considered a time range covering 60 days before and 60 days after an SSW. Of course, three events do not allow proper statistical material, but some tendencies can be traced. Preliminarily, there is a TOC increase by ~100 DU at Amundsen-Scott (located at the South Pole) near the SSW date. The corresponding increase in the Atlantic longitudinal sector (Rothera, Faraday/Vernadsky, and even mid-latitude Ushuaia station) occurred several days later. It is noticed that after several weeks, TOC values in the Atlantic sector become lower than climatological ones, which a partial recovery of the polar vortex can cause. In the opposite Australian longitudinal sector, TOC values are maintained over the climatological level by tens of DU at least 30–40 days before the SSW. Consequently, the SSW events seem to be prepared by stratospheric processes connected with the intensification of the TOC zonal maximum.

This work was partly supported by the projects of the Australian Antarctic Division and by the International Center of Future Science, Jilin University, under Grant No G2023129024.