A brand new examine reveals the Antarctic ozone gap is bigger and extra enduring than thought, with complicated components past CFCs contributing to its persistence and impression on the Southern Hemisphere’s local weather.
Regardless of public notion, the Antarctic ozone gap has been remarkably huge and long-lived over the previous 4 years, and College of Otago researchers consider chlorofluorocarbons (CFCs) aren’t the one issues accountable.
In a examine, printed as we speak (November 21) within the journal Nature Communications, the group analyzed the month-to-month and day by day ozone adjustments, at completely different altitudes and latitudes throughout the Antarctic ozone gap, from 2004 to 2022.
Deepening Considerations About Ozone Depletion
Lead creator Hannah Kessenich, PhD candidate within the Division of Physics, says they discovered there may be a lot much less ozone within the middle of the ozone gap in comparison with 19 years in the past.
“Because of this the outlet will not be solely bigger in space, but in addition deeper all through most of spring.
“We made connections between this drop in ozone and adjustments within the air that’s arriving into the polar vortex above Antarctica. This reveals the current, giant ozone holes might not be brought about simply by CFCs,” she says.
Ozone Gap Persistence Regardless of Montreal Protocol
Whereas the Montreal Protocol on Substances that Deplete the Ozone Layer, which has been in place since 1987, regulates the manufacturing and consumption of artificial chemical substances recognized to deplete the ozone, the researchers consider different complicated components are additionally contributing to the ozone gap.
“Most main communications in regards to the ozone layer over the previous few years have given the general public the impression that the ‘ozone challenge’ has been solved.
“Whereas the Montreal Protocol has vastly improved our state of affairs with CFCs destroying ozone, the outlet has been amongst the biggest on document over the previous three years, and in two of the 5 years previous to that.
“Our evaluation ended with knowledge from 2022, however as of as we speak the 2023 ozone gap has already surpassed the scale of the three years prior – late final month it was over 26 million km2, almost twice the realm of Antarctica.”
Ozone Variability and Local weather Impression
Ms. Kessenich believes understanding ozone variability is necessary due to the foremost position it performs within the Southern Hemisphere’s local weather.
“Everyone knows in regards to the current wildfires and cyclones in Australia and New Zealand and the Antarctic ozone gap is a part of this image.
“Whereas separate from the impression of greenhouse gases on local weather, the ozone gap interacts with the fragile steadiness within the environment. As a result of ozone normally absorbs UV mild, a gap within the ozone layer cannot solely trigger excessive UV ranges on the floor of Antarctica, however it will possibly additionally drastically impression the place warmth is saved within the environment.
“Downstream results embrace adjustments to the Southern Hemisphere’s wind patterns and floor local weather, which may impression us domestically.”
She is fast to allay fears about excessive UV rays, although.
“New Zealanders needn’t fear about making use of additional sunscreen this 12 months because the Antarctic ozone gap is usually not open above New Zealand – it’s principally positioned immediately over Antarctica and the South Pole.”
Reference: “Potential drivers of the current giant Antarctic ozone holes” 21 November 2023, Nature Communications.