SENSITIVITY OF TRANSIENT EDDIES TO CLIMATE-CHANGE IN THE CCC GENERAL-CIRCULATION MODEL

We use eddy life-cycle simulations to evaluate the response of atmosph eric transient eddies to a global warming caused by CO2 doubling in th e CCC general circulation model. In simulations using Northern Hemisph ere winter conditions, transient waves attain larger kinetic energy an d encompass a wider range of latitudes in the warmer climate. This beh aviour contrasts with a previous investigation that used output from t he NCAR and GFDL models. Our analysis indicates two primary factors fo r the difference between model responses: (1) a smaller change in the mid-latitude temperature gradient in the CCC model, which allows (2) i ncreased atmospheric water vapour in mid-latitudes to catalyze a more rapidly evolving life-cycle.