Ozone hole over Antarctica just keeps getting bigger and bigger

Mt Herschel (3335m asl) from Cape Hallet with Seabee Hook penguin colony in Foreground. Antarctica.
Credit – Andrew Mandemaker. (CC BY-SA 2.5)

A new concern over the ozone layer. Research finds the Antarctic ozone hole has been massive and long-lived over the past four years. This leads researchers from the University of Otago to believe chlorofluorocarbons (CFCs) are not the only factors to blame.

Specifically, the researchers have found there is much less ozone in the centre of the ozone hole compared to 19 years ago. This means the hole is getting both larger and deeper.

The fact that the hole is getting bigger means that other factors must be at play other than CFCs, given the global restrictions put in place in relation to these classes of chemicals (as per the Montreal Protocol on Substances that Deplete the Ozone Layer of 1987).

According to lead researcher Hannah Kessenich: “Most major communications about the ozone layer over the last few years have given the public the impression that the ‘ozone issue’ has been solved.”

She adds: “While the Montreal Protocol has vastly improved our situation with CFCs destroying ozone, the hole has been amongst the largest on record over the past three years, and in two of the five years prior to that.

In terms of the extent of the challenge, Kessenich reveals: “Our analysis ended with data from 2022, but as of today the 2023 ozone hole has already surpassed the size of the three years prior — late last month it was over 26 million kilometres squared, nearly twice the area of Antarctica.”

Another reason for being concerned about the trend and for studying it in more detail is, Kessenich indicates, is because understanding ozone variability connects ozone depletion patterns to the Southern Hemisphere’s climate, such as the wildfires and cyclones in Australia and New Zealand.

Notably, since ozone usually absorbs UV light, then a hole in the ozone layer causes extreme UV levels on the surface of Antarctica; moreover, it also drastically impacts where heat is stored in the atmosphere, altering the Southern Hemisphere’s wind patterns and surface climate.

The research appears in the journal Nature Communications, titled “Potential drivers of the recent large Antarctic ozone holes.”

In related news, the Hunga Tonga-Hunga Ha’apai volcano changed the chemistry and dynamics of the stratosphere in the year following the eruption, leading to unprecedented losses in the ozone layer of up to 7 percent over large areas of the Southern Hemisphere.

Dr. Tim Sandle is Digital Journal’s Editor-at-Large for science news.
Tim specializes in science, technology, environmental, business, and health journalism. He is additionally a practising microbiologist; and an author. He is also interested in history, politics and current affairs.