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

TL;DR

This paper investigates early signs of anomalous behavior in the 2019 Antarctic ozone hole, linking planetary wave activity, sea surface temperatures, and atmospheric oscillations to potential disruptions and regional weather impacts.

Contribution

It identifies key atmospheric and oceanic factors that indicated an early and potentially major disruption of the Antarctic ozone hole in 2019.

Findings

Large planetary wave activity signaled possible major SSW in 2019

Warm tropical SSTs contributed to stratospheric disturbances

Transitioning QBO phase influenced ozone depletion patterns

Abstract

The level of quasi-stationary planetary wave (QSW) activity in the Antarctic winter stratosphere provides insights into the likely behavior of the ozone hole in the following spring months. Observation of an 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 area 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 Antarctic SSW in 2002. Under these conditions, the Antarctic SSW in 2019 has the potential to become a major SSW. The additional factors disturbing the Antarctic stratosphere in 2019 was anomalously warm sea surface temperatures (SSTs) in the central tropical Pacific Ocean and western Indian Ocean, and the descending easterly phase of the Quasi-Biennial Oscillation. The combination of these factors - the large amplitude of the QSW, the warm tropical SSTs and transitioning phase of the QBO - has the potential to cause the early disruption of the ozone hole and reduce the overall level of ozone depletion in 2019, and may also have important regional consequences for weather conditions in the Southern Hemisphere.