Scientists announced that the record-level ozone depletion over the Arctic has recovered—but it’s not related to the lockdown.
In spring, an “unprecedented hole” developed in the ozone layer over the Northern Hemisphere. Scientists monitoring it at Copernicus’ Atmospheric Monitoring Service (CAMS), recently announced that the hole has closed again.
Ozone is the naturally occurring gas that protects life on Earth from the sun’s damaging UV radiation. The three reactive oxygen molecules form a layer that acts as a sort of sunscreen that absorbs the harmful rays that can cause cancer and suppress immune systems.
According to a press release from NASA, the ozone reached its lowest levels on March 12 this year. While these levels are alarmingly low, especially for this time of year, holes similar in size were seen in 1997 and 2011.
The unprecedented 2020 northern hemisphere #OzoneHole has come to an end. The #PolarVortex split, allowing #ozone-rich air into the Arctic, closely matching last week's forecast from the #CopernicusAtmosphere Monitoring Service.
— Copernicus ECMWF (@CopernicusECMWF) April 23, 2020
However, neither the cause nor the recovery has been linked to human activity or air quality. Instead, it’s most likely to be the polar vortex that led to the unusual winter warmth and the large ozone hole, CAMS explained.
This article covers the full basics of what led to this Arctic ozone hole and why it's so unusual: https://t.co/Nf6AfjaYRi Basically it was caused by an unusually strong and long-lived polar vortex, and has ended because that polar vortex ended.
— Copernicus ECMWF (@CopernicusECMWF) April 26, 2020
A polar vortex is a large area of low pressure and cold air that surrounds both of Earth’s poles, according to the National Weather Service. The “vortex” refers to the counter-clockwise flow of air that helps keep the poles frosty. These have always existed, but they usually weaken in the summer and strengthen in the winter.
While the Antarctic ozone hole in the Southern Hemisphere occurs annually, these ozone depletion levels are uncommon to see in the Northern Hemisphere.
Antarctic ozone holes are caused by chemicals such as chlorine and bromine migrating into the stratosphere, but since the Montreal Protocol went into place the hole is smaller than it has ever been since it was first discovered.