Scientists found in 2019 that the Antarctic ozone hole had reached its lowest annual peak since tracking began in 1982, but a 2020 update on this atmospheric anomaly – like other things this year – offers a sobering perspective.
“Our observations show that the ozone hole in 2020 has grown rapidly since mid-August and covers most of the Antarctic continent – well above average in size,” explains project manager Diego Loyola of the German Aerospace Center.
New measurements from the European Space Agency's Copernicus Sentinel-5P satellite show that on October 2 this year, the ozone hole reached its maximum size of about 25 million square kilometers.
This puts it in about the same place as the ozone holes of 2018 and 2015, which peaked at 22.9 and 25.6 million square kilometers, respectively.
“The degree of development of the ozone hole varies greatly each year,” says atmospheric scientist Vincent-Henri Pösch of the European Center for Medium-Range Weather Forecasts.
The ozone hole over Antarctica shrinks and grows every year, with the concentration of ozone inside the hole decreasing as temperatures in the stratosphere get colder.
This happens, in particular, when polar stratospheric clouds form at temperatures below –78 ° C (–108.4 ° F), chemical reactions destroy ozone molecules in the presence of solar radiation.
“With the return of sunlight to the South Pole in recent weeks, we have seen continued ozone depletion in the area,” says Peuch.
While we know that human activities on this front are helping us fix the Antarctic ozone hole, the constant fluctuations from year to year indicate that the process will be long.
A 2018 World Meteorological Organization estimate found ozone concentrations over Antarctica to return to relatively normal levels until the 1980s by about 2060.
