Researchers from the German Aerospace Center (DLR) Earth Observation Center (EOC) used Earth-observation satellites to determine the size of ozone hole. The Ozone hole over Antarctica currently extends more than 26 million square kilometres, an area larger than North American continent. In 2006, the Ozone hole was 27 million square kilometers.
“This example shows the enormous importance of Earth observation—such large-scale change processes can only be observed and understood with satellites,” says Stefan Dech, director of the EOC.
Intense ozone depletion over Antarctica recurs annually, because the concentration of chlorofluorocarbons (CFCs) becomes enriched while low temperatures prevail during the southern hemisphere winter. Now in the southern hemisphere spring, additional sunlight causes these substances to exert their ozone-depleting effect. In recent years, the ozone hole appeared to have stabilised, suggesting a gradual recovery of the ozone layer.
Source: Earth Imaging Journal