There is some speculation that the unusual behavior of the ozone layer in 2023 is a result of the Tongan underwater volcano eruption in January 2022.

The immense amount of water vapor that was injected into the atmosphere likely just started reaching the south polar region after the end of the 2022 ozone hole, Antje said.

The water vapor could have led to a heightened formation of polar stratospheric clouds, allowing chlorofluorocarbons to react and accelerate ozone depletion.