Early indications of anomalous behaviour in the 2019 spring ozone hole over Antarctica

ABSTRACT

The level of quasi-stationary planetary wave (QSW) activity in the Antarctic winter stratosphere provides insights into the likely behaviour of the ozone hole in the following spring months. Observation of anomalously large amplitude of the QSW in winter stratospheric temperatures is an indicator that strong disturbances to the polar vortex are likely to occur, and may lead to large reductions in both the area of the Antarctic ozone hole and the overall amount of stratospheric ozone that is depleted. In the sudden stratospheric warming (SSW) preconditions in 2019, the maximum QSW amplitude over Antarctica in August was approximately 12 K, which was only 2 K less than conditions prior to the unprecedented major SSW in 2002. The additional factors disturbing the Antarctic stratosphere in austral winter 2019 were anomalously warm sea surface temperatures in the central tropical Pacific Ocean and the western Indian Ocean, and the descending easterly phase of the Quasi-Biennial Oscillation. Under these preconditions, the Antarctic ozone hole in 2019 had the potential to demonstrate the early disruption and reduced level of the ozone depletion that has been confirmed by the satellite ozone observations. The anomalous ozone hole may also have important regional consequences for weather conditions in the Southern Hemisphere.

Acknowledgments

This work was supported in part by the College of Physics, International Center of Future Science, Jilin University, China; by Taras Shevchenko National University of Kyiv, project 19BF051-08. We thank the NOAA Climate Prediction Center, NCEP–NCAR reanalysis, NASA GSFC Atmospheric Chemistry and Dynamics Laboratory team, NASA GSFC Ozone Watch and Climate System Monitoring of Japan Meteorological Agency for data of the atmospheric parameters, Met Office Hadley Centre team for HadISST temperature data and the KNMI for the Climate Explorer research tool.