Antarctic 2020 record-breaking ozone hole closed in late December "after an exceptional season due to natural weather conditions and the continued presence of ozone-depleting substances in the atmosphere."
This was announced by the World Meteorological Organization (OMM-WMO), recalling that it had grown rapidly since mid-August, reaching a peak of about 24.8 million square kilometers on September 20, spreading over much of the Antarctic continent.
The Omm recalls that "it was the longest and one of the largest and deepest holes since monitoring began 40 years ago".
This hole was caused by a strong, stable and cold polar vortex and very cold temperatures in the stratosphere (the layer of the atmosphere between about 10 km and about 50 km of altitude), explains the Omm, the same meteorological factors that have contributed to the record-breaking 2020 Arctic ozone hole. A situation in contrast to the unusually small and short-lived Antarctic ozone hole in 2019. "The last two seasons of the ozone hole demonstrate the its variability from year to year and improve our understanding of the factors responsible for its formation, extent and severity, "said Oksana Tarasova, head of the atmospheric environment research division of the OMM.
"We need continuous international action - he adds - to implement the Montreal Protocol" which bans the emissions of chemicals that deplete the ozone layer.