Atmospheric Chemistry Program Seminar: Marina Friedel, IAC, ETH Zuerich

Springtime Arctic ozone depletion forces northern hemisphere climate anomalies
Marina Friedel,
IAC, ETH Zuerich
"Large-scale chemical depletion of ozone due to anthropogenic emissions of chlorofluorocarbons (CFCs) can occur, albeit infrequently, over the Arctic. Such ozone depletion events are consistently followed by surface temperature and precipitation anomalies over vast parts of the Northern Hemisphere. Using chemistry-climate models, it can be shown that the loss of stratospheric ozone is an important cause of these surface anomalies, as it leads to persistently cold temperatures in the lower stratosphere and alters stratospheric dynamics. Including chemical processes involving ozone in forecast models could therefore increase predictability on a sub-seasonal to seasonal scale. Similarly, the long-term trend in Arctic ozone caused by the decline of CFCs also has important implications for stratospheric temperature and dynamics. The imminent recovery of the ozone layer will heat the polar stratosphere, and its fingerprint is expected to be seen all the way down to the surface, as model simulations show. Therefore, a realistic representation of ozone in climate models is required to reduce uncertainty in climate projections.”