Researchers from the European Union’s Copernicus Atmosphere Monitoring Service (CAMS) reported that the single largest ozone hole ever detected over the Arctic has finally closed.
Reasons behind the Arctic Ozone hole
The Arctic ozone hole opened this year only because the cold air was concentrated in the area for much longer than is typical. The hole in the ozone layer — a portion of Earth’s atmosphere that protects the planet from ultraviolet radiation — first opened over the Arctic in March 2020 when unusual wind conditions trapped frigid air over the North Pole for several weeks in a row.
Those winds, known as a polar vortex, created a circular cage of cold air that led to the formation of high-altitude clouds in the region. According to the European Space Agency (ESA), the clouds mixed with man-made pollutants like chlorine and bromine, eating away at the surrounding ozone gas until a massive hole roughly three times the size of Greenland opened in the atmosphere.
What is Polar Vortex?
A polar vortex is a large area of low pressure and cold air that surrounds both of Earth’s poles. Polar vortexes always exist, but they typically weaken during the summer and strengthen in the winter. The polar vortex in the Arctic is typically weaker due to the presence of nearby land as well as mountain ranges that disturb the weather more so than its counterpart to the south.
Differences between Arctic and Antarctic Ozone
Unlike the hole that developed over the Arctic, the Antarctic ozone hole in the Southern Hemisphere is typically caused by chemicals such as chlorine and bromine migrating into the stratosphere. This has caused an ozone hole to develop in the Antarctic annually for the last 35 years.
