UV Dosage Levels in Summer: Increased Risk of Ozone Loss from Convectively Injected Water Vapor

Abstract

Water In, Ozone Out: The danger of stratospheric ozone loss burst into public awareness in the 1980s, when the Antarctic ozone hole was discovered and described. Since then, the specter of ozone depletion in other locations, notably the Arctic, has been identified. Ozone loss is not confined to high latitudes, however, nor is it only the result of the addition of anthropogenic compounds containing chlorine and bromine in the stratosphere, as Anderson et al. (p. 835 , published online 26 July; see the Perspective by Ravishankara ) now demonstrate. Data from the atmosphere above the continental United States revealed that convective injection of water vapor into the stratosphere affects the free radical chemistry involving the (mostly anthropogenic) chlorine and bromine, thus accelerating ozone loss. This process could become important in the stratospheric ozone budget if the frequency and intensity of these water-injection events, which are most common in the summer, increase as a result of global warming.