This Year’s Ozone Layer Hole ‘Larger than Usual’
Scientists say that the ozone hole is unusually large for this stage in the season, and is growing rapidly.
The hole in the ozone layer that develops annually is now “rather larger than usual” and bigger than Antarctica, researchers from the Copernicus Atmosphere Monitoring Service (CAMS) revealed.
They stated that this year’s hole is growing quickly and is larger than 75% of ozone holes at this stage in the season since 1979.
Moreover, according to the European Space Agency, this year's ozone hole appears to be similar in size to 2020's, with a current area of roughly 23 million square km, larger than the whole of Antarctica.
"This ozone evolution is what we would expect given the current atmospheric conditions. The progress of the ozone hole over the coming weeks will be extremely interesting,” Antje Inness, a senior scientist at European Centre for Medium-Range Weather Forecasts, which operates the CAMS, is quoted as saying.
2021 - the ozone hole so far 🛰️🌎— ESA EarthObservation (@ESA_EO) September 16, 2021
According to @CopernicusECMWF, the 2021 ozone hole has considerably grown in the last two weeks and is now larger than 75% of ozone holes at that stage in the season since 1979.
📽️Size of the 2021 ozone hole#OzoneDay pic.twitter.com/3eMd3wVGUU
What is the Ozone?
The Ozone lies at about 11-40km above the Earth’s surface, in the stratosphere. It protects the planet from sunrays, repelling ultraviolet radiation. Every year, a hole forms during the late winter of the southern hemisphere as the sun causes ozone-depleting reactions, which involve chemically active forms of chlorine and bromine derived from human-made compounds. In a statement, Copernicus said that this year’s hole “has evolved into a rather larger than usual one”.
🌐The 2021's #OzoneHole has evolved into a rather larger than usual one. How do you think it sizes up next to other recent years? Compare it side-by-side with our decades-long record— Copernicus ECMWF (@CopernicusECMWF) September 16, 2021
More on how the #CopernicusAtmosphere Monitoring Service tracks #ozone➡️https://t.co/U1k51lHMyp pic.twitter.com/mF0EzYTWDC
The hole's expansion is normal, but to what extent?
According to CAMS Director, Vincent-Henri Peuch, the ozone hole that appeared last year began innocuously enough, but later became one of the longest-lasting examples of the phenomena ever seen, eventually closing in late December.
Scientists note that the hole normally expands to a maximum area of around 20.7 million square km, in years with regular weather conditions.
Despite these natural variations, experts predict that the hole will close permanently by 2050 as a result of the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, which was ratified by all UN countries.
The history of the hole expansion and closure
In 2019, NASA reported the smallest ozone hole ever recorded, peaking at 16.4 million square km in early September, before shrinking to less than 10 million square km throughout the rest of September and October. However, in 2015, meteorological agencies recorded one of the largest and most persistent ozone holes over the South Pole, with its vortex area reaching over 32 million square km.
The 2020 Arctic ozone hole was also very large and deep and peaked at roughly three times the size of the continental US.
The Antarctic ozone hole usually reaches its peak between mid-September and mid-October. When temperatures start to rise high up in the stratosphere 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.