In 2019, scientists revealed that the Antarctic ozone hole had reached its smallest annual peak since tracking began in 1982, but an update on this atmospheric anomaly in 2020 – like other things this year – brings an exciting perspective. is.
“Our observations suggest that the 2020 ozone hole has increased rapidly since mid-August, and covers much of the Antarctic continent,” explains Diego Loyola, project manager at the German aerospace center.
New measurements from the European Space Agency’s Copernicus Sentinel-5P satellite suggest that the ozone hole reached its maximum size of 25 million square kilometers (about 9.6 million square miles) on 2 October this year.
It pours into almost the same ballpark as the ozone hole of 2018 and 2015, recording peaks of 22.9 and 25.6 million square kilometers, respectively.
“There is so much variability in the ozone hole incidence every year,” says atmospheric scientist Vincent-Henri Pech of the European Center for Medium-Range Weather Forecast.
“The ozone hole of 2020 looks like the one from 2018, which was also a very large hole, and is definitely in the upper half of the pack for the last 15 years.”
The ozone hole over Antarctica shrinks and fluctuates from year to year, fluctuating from year to year, when there is ozone concentration inside the hole when the temperature in the stratosphere cools down.
When this occurs – in particular, when polar stratospheric clouds form at temperatures less than −78 ° C (−108.4 ° F) – chemical reactions destroy ozone molecules in the presence of solar radiation.
“With sunlight returning to the South Pole in the past weeks, we saw ozone depletion continue in the region.”
“After an unusually small and short-lived ozone hole in 2019, which was driven by special meteorological conditions, we are registering once again this year on a larger scale, which confirms that we need ozone-depleting chemicals Requires the Montreal Protocol to be implemented. ”
The Montreal Protocol was a milestone in humanity’s environmental achievements, phasing out the manufacture of harmful chlorofluorocarbons (CFCs) – chemicals previously used in refrigerators, packaging, and sprays – that destroy ozone molecules in sunlight We do.
While we now know that humanitarian action on this front is helping us fix the Antarctic ozone hole, the fluctuations going on from year to year suggest that the medical process will be longer.
A 2018 assessment by the World Meteorological Organization found that ozone concentrations over Antarctica would return to normal levels before about 1980 by 2060. To realize that goal, we have to stick to protocol and ride the bumps, like we’re seeing this year.
While the maximum peak of 2020 is not the largest on record – which was traced back to 2000, with 29.9 million square kilometers of holes – it is still significant, with the hole also one of the deepest in recent years.
Researchers say the 2020 event is driven by a strong polar vortex: a wind event that holds stratospheric temperatures above Antarctica freezing.
Conversely, warmer temperatures last year brought about the record-low ozone hole size of 2019, as scientists explained back.
“It’s important to recognize what we’re seeing [in 2019] Warmer is caused by stratospheric temperatures, ”said Paul Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
“This is not an indication that atmospheric ozone is on a fast track to a sudden recovery.”
While there may be no fast track, and we can expect some more scary peaks in the coming years, the Montreal Protocol is our back. If we are right, we are going to get there one day.