Publié le 4 novembre 2020
Persistent cold temperatures and strong circumpolar winds, also known as the polar vortex, supported the formation of a large and deep Antarctic ozone hole that should persist into November, NOAA and NASA scientists reported today.
The annual Antarctic ozone hole reached its peak size at about 9.6 million square miles (24.8 million square kilometers), roughly three times the area of the continental United States, on Sept. 20. Observations revealed the nearly complete elimination of ozone in a 4-mile-high column of the stratosphere over the South Pole.
A cold and stable Antarctic vortex supported the development of the 12th-largest ozone hole on record in 2020. The hole reached its peak extent on Sept. 20 at 24.8 million square kilometers.
Credits: NASA's Goddard Space Flight Center/Scientific Visualization Studio
The year 2020 will go down as having the 12th largest ozone hole by area in 40 years of satellite records, with the 14th lowest amount of ozone in 33 years of balloon-borne instrumental measurements, the scientists said. Ongoing declines in levels of ozone-depleting chemicals controlled by the Montreal Protocol prevented the hole from being as large as it would have been under the same weather conditions decades ago.