Antarctic Ozone Depletion Challenges Previously Reported Recovery Trends

• 27 Nov 2023

The core of the Antarctic ozone in mid-spring has experienced a 26% reduction since 2004, challenging previously reported recovery trends in total ozone, according to a recent study published.

Key Points

• Montreal Protocol Impact: The Montreal Protocol, effective since 1987, successfully controlled ozone-depleting substances. However, recent years (2020-2022) have seen the re-emergence of large ozone holes over Antarctica in mid-spring, while early spring shows a slight ozone increase.
• Climate Variability: Antarctic stratospheric ozone's role in climate variability across the Southern Hemisphere underscores the importance of understanding ozone variability.
• Continuous Monitoring: The study emphasizes the need for continuous monitoring and evaluation of the ozone layer, especially with the changing dynamical state of Earth's climate.
• Assessment Methodology: Researchers analyzed monthly and daily ozone changes between 2001-2022, excluding data from 2002 and 2019 due to anomalous ozone hole breakup. Different stratospheric layers were examined during key springtime months from September to November.
• Satellite Data Impact: When considering satellite data from 2022, previously reported recovery trends in Antarctic spring total column ozone disappeared. The middle stratosphere has witnessed a continued, significant ozone reduction since 2004, amounting to a 26% loss in the core of the ozone hole.
• Potential Drivers: Dynamical changes in the mesosphere, the atmospheric layer above the stratosphere, and the ozone layer, may be driving the observed reduction in the core of the ozone hole.
• Persistent Ozone Hole: Changes in the Southern Hemisphere atmosphere contribute to a persistent Antarctic ozone hole, indicating ongoing challenges in ozone recovery.