A hole in the ozone, the largest on record over the Arctic, that developed earlier this year has closed, researchers said.
The European Space Agency believes the hole was caused by unusual atmospheric conditions, including a polar vortex, not human activity, CNET reported.
A polar vortex is a strong and sustained push of cold, swirling air.
The European Commission’s Copernicus satellite tracked the hole. The ozone works as a barrier protecting Earth from the sun’s harmful ultraviolet radiation.
Holes over Antarctica form seasonally. While Arctic ozone holes are more rare, this is not the first time one has formed. A similar event caused an ozone hole in 2011, CNET reported.
A hole over Antarctica is showing signs of reducing since a 2018 chemical ban, according to NASA.