An estimate of the impact of observed ozone losses on stratospheric temperature

The climatic impact of the observed stratospheric ozone changes since 1980 was studied in simulations with the Berlin Climate Middle Atmosphere Model (CMAM). The model was run with prescribed ozone climatologies of the years 1980 and 2000, derived from the newest WMO assessment of ozone trends. It is shown that in the northern hemisphere stratosphere, the temperature decreases as a reaction to the 20 year ozone changes. Whereas the patterns of the observed stratospheric cooling for that period are reproduced in the model, its magnitude is underestimated, indicating an impact of other factors on stratospheric temperature.