Scientists from the Copernicus Atmosphere Monitoring Service (CAMS) who have been closely monitoring the development of this year’s Antarctic ozone hole have found that it has grown larger than the size of Antarctica.
Ozone layer that wraps the planet absorbs a portion of the harmful radiation from the sun called the UVB that is linked to skin cancers and cataracts in humans. It is also known to harm some crops and marine life. While the ozone concentration in the layer varies naturally with seasons and latitudes, since 1970s the layer has shown depletion beyond natural processes that is linked to human activities.
This is the first status update by CAMS on the International Day for the Preservation of the Ozone Layer on the ozone hole that appears every year during Austral spring or spring in the southern hemisphere. Copernicus is the flagship Earth observation programme of the European Union.
“This year, the ozone hole developed as expected at the start of the season. It seems pretty similar to last year’s, which also wasn’t really exceptional in September, but then turned into one of the longest-lasting ozone holes in our data record later in the season,” said Vincent-Henri Peuch who is the director of the Copernicus Atmosphere Monitoring Service. “Now our forecasts show that this year’s hole has evolved into a rather larger than usual one. The vortex is quite stable and the stratospheric temperatures are even lower than last year. We are looking at a quite big and potentially also deep ozone hole.”
Considerable growth after standard start
During the Southern Hemisphere spring season from August to October, the ozone hole forms annually over the Antarctic, reaching a maximum between mid-September and mid-October. When temperatures high up in the stratosphere start to rise in late Southern Hemisphere spring, ozone depletion slows, the polar vortex weakens and finally breaks down, and by December, ozone levels usually return to normal.
The 2021 ozone hole has considerably grown in the last week and is now larger than 75% of ozone holes at that stage in the season since 1979.
The International Day for the Preservation of the Ozone Layer was created by the United Nations to commemorate the signing of the Montreal Protocol in 1987 by 196 states and the EU, in which the main ozone-depleting chemicals were banned.
Since the ban on halocarbons, the ozone layer has shown signs of recovery, but it is a slow process and it will take until the 2060s or 2070s to see a complete phasing out of the ozone depleting substances. It is essential to maintain monitoring efforts in order to ensure that the Montreal protocol keeps being enforced.
CAMS’ operational monitoring of the ozone layer is using computer modelling in combination with satellite observations in a similar way to weather forecasts in order to provide a comprehensive three-dimensional picture of the state of the ozone hole.
Climate change and its mitigation is the key theme at the upcoming UN climate change conference (COP26) that will be held in November this year in Glasgow, United Kingdom.