The massive ozone hole that formed over the North Pole has finally closed, scientists have announced.
Researchers from the European Union’s Copernicus Atmosphere Monitoring Service (CAMS) who were tracking the record-breaking ozone hole over the Arctic tweeted last Thursday:
“The unprecedented 2020 Northern Hemisphere ozone hole has come to an end.”
The hole, which was the single largest such ozone hole ever detected in the arctic, first opened in late March as unusual wind conditions trapped frigid air over the North Pole for several consecutive weeks.
However, scientists took pains to point out that the closing of the hole has nothing to do with drop in emissions recorded across the world as a result of lockdown measures meant to curb the coronavirus.
On Twitter, the group wrote:
“COVID-19 and the associated lockdowns probably had nothing to do with this.
“It’s been driven by an unusually strong and long-lived polar vortex, and isn’t related to air quality changes.”
Live Science reports that a polar vortex is comprised of powerful winds that create a circular cage of cold air that leads to the formation of high-altitude clouds in the region. The clouds mixed with harmful human-made chemicals such as chlorine and bromine, which migrated into the stratosphere and accumulated inside the vortex.
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
More on the NH Ozone hole➡️https://t.co/Nf6AfjaYRi pic.twitter.com/qVPu70ycn4
The chemicals then ate away at surrounding gases, thinning the ozone layer and forming a huge hole approximately three times the size of Greenland in the atmosphere, according to a European Space Agency (ESA) statement.
The ozone layer is the layer in the Earth’s stratosphere that is responsible for absorbing the ultraviolet (UV) rays of the Sun, effectively filtering out radiation that causes skin cancer among humans, destroys crops, and disrupts marine ecosystems among other devastating effects on the planet.
The ozone layer has faced decades of degradation thanks to the use of harmful chemical compounds such as chlorofluorocarbons, halons, hydrochlorofluorocarbons, and other organic and synthetic (human-made) ozone-depleting compounds that are commonly used in refrigerators, aerosols, and a range of industrial processes.
The startling decline of the ozone layer became such a dire matter of concern that in 1987, governments agreed to the Montreal Protocol, an international treaty meant to phase out the production and use of ozone-depleting chemicals.
However, ozone holes have continued to form annually in the Antarctic due to a failure to sufficiently check the amount of human-made chemicals that continue to make their way into the stratosphere. Scientists believe that this will remain a seasonal phenomenon in the future.
In October, the ozone hole shrank to its smallest size ever recorded, mainly due to the unusually hot climate conditions above Antarctica caused by global warming.
In the Arctic, polar vortexes tend to be far weaker, which means that the conditions which eat away at ozone gases aren’t typically found—hence the “unprecedented” nature of this ozone hole.
According to a 2018 study by the World Meteorological Organization, the southern ozone hole has been shrinking at a rate of 1 percent to 3 percent per decade since 2000, meaning that it won’t heal entirely until about 2050. Credit is also due to the Montreal Protocol for the apparent healing of the ozone layer.