Largest ozone hole ever recorded in Arctic just slammed shut, experts say. Here’s why
The largest ozone hole to ever open up over the Arctic has now closed, media outlets report.
The demise of a long-lived and exceptionally strong polar vortex — a mass of swirling low pressure, cold air — is to blame for the closure after it created the hole earlier this spring, the scientists who were tracking it announced in a tweet.
The news is welcomed because the now-filled ozonelayer can return to its job of protecting those on land from harmful ultraviolet radiation that can cause sunburns and skin cancers, according to NASA.
However, lockdowns related to the coronavirus pandemic did not play a part, unlike the many reports of drops in harmful chemicals in the atmosphere due to decreases in travel and business closures.
“Actually, COVID19 and the associated lockdowns probably had nothing to do with this,” the Copernicus Atmosphere Monitoring Service (CAMS) tweeted. “It’s been driven by an unusually strong and long-lived polar vortex, and isn’t related to air quality changes.”
The last time such an intense ozone depletion occurred over the Arctic was during spring 2011, but “2020 seems on course to be even stronger,” a CAMS press release said.
Polar vortexes are usually much weaker in the Northern Hemisphere where the Arctic lies, typically because of the nearby mountain ranges that disturb weather’s flow, CAMS said, unlike in Antarctica on the opposite hemisphere where these holes are more common.
Temperatures were also lower than usual, allowing the formation of polar stratospheric clouds that resulted in bigger drops in ozone, CAMS said.
The news also comes after NASA reported that ozone levels above the Arctic reached a record low in March. This was caused by “unusually weak upper atmospheric ‘wave’ events’” that drive air movements, NASA said in a press release.
But when the polar vortex came to an end, ozone-rich air rushed into the hole and closed it, CAMS said.
Scientists reported that the hole was about three times the size of Greenland, according to CBS News.
Ozone is a molecule mostly found in the stratosphere — the layer of the atmosphere just above where planes fly — and protects people from harmful UV rays, but on the ground, it can be harmful to breathe and can cause lung damage, according to NASA.
Unlike the hole in the Arctic, the one that has been growing over the Antarctic for the last 35 years is caused by chemicals such as chlorofluorocarbons that come from hairsprays and refrigerators.
Last year, however, the hole reached its smallest size since its discovery, NASA reported.
This story was originally published April 29, 2020 at 2:32 PM with the headline "Largest ozone hole ever recorded in Arctic just slammed shut, experts say. Here’s why."
