Its hole in the ozone layer over Antarctica grew unusually large and lingered longer than typical in recent years. Data from the Atmospheric Monitoring Service of the European Copernicus CAMS satellite system show that the shutdown period was not only substantial but also extended beyond the usual timeframe.
According to CAMS, this behavior has recurred over the last three years and stands out because it differs from the patterns observed in the prior four decades.
The Antarctic ozone hole typically begins to open in the spring of the southern hemisphere, around late September, with a decline starting in October and a closing by November.
Evidence from CAMS over the last three years indicates a departure from this cycle, with the ozone hole remaining larger through November and not fully closing until December.
Climate factors may be at play
CAMS notes that multiple factors influence these changes, including strong atmospheric eddies and persistently low temperatures. These conditions have repeatedly produced large, long-lasting ozone holes.
There is a possible association with climate change, which tends to cool the stratosphere. Yet seeing three unusual ozone holes in a row is highly unusual, and researchers continue to study the phenomenon.
The closures for 2020 and 2021 occurred on December 28 and December 23 respectively, and scientists expect this year’s deficit to close in the near term.
The Antarctic ozone holes have been unusually persistent and large, covering more than 15 million square kilometers for much of November, a surface comparable in size to the continent itself.
Despite the recent size and duration, there are ongoing signs of improvement in the ozone layer, according to CAMS data.
Thanks to the Montreal Protocol, concentrations of ozone-depleting substances have fallen gradually since the late 1990s, and within fifty years these substances are expected to return to preindustrial levels in the stratosphere, reducing or eliminating future ozone holes under typical polar conditions.
Continued monitoring and research are essential to understand the role of atmospheric dynamics, temperature fluctuations, and the broader climate context in shaping the recovery of the ozone layer.
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