Abstract: An off-line coupling model system consisting of a global three-dimensional atmospheric chemistry transport model MOZART-2 and a global three-dimensional atmospheric circulation model CAM2 is newly set up and applied to simulate tropospheric ozone over Europe. Comparison of model results with multi-year ground level observations over Europe shows that the seasonal variations of surface ozone mixing ratios can be generally reproduced with slight overestimations at Hohenpeissenberg and a little underestimation at Kollumerwaard; in addition, the magnitude and general features of surface CO seasonal variations can also be well captured. Compared with ozonesonde observation data at Lindenberg in Germany and Sodankyla in Fanland, the vertical gradient and magnitude of tropospheric ozone mixing ratios can be well reproduced, especially in autumn when the simulated mid-troposphere ozone levels at above both sites are in better agreement with observations. Compared with ozonesonde observations at Hohenpeissenberg in Germany and Nyalesund in Norway, seasonal cycles of ozone concentrations at 300hPa, 500hPa and 800hPa can also be fairly reproduced, especially at 300hPa. Overall, good simulations of tropospheric ozone concentrations over Europe by using this model system can lay a scientific basis for further study of Tran-Eurasian transport of pollutants.

Key words: MOZART-2, CAM2, Tropospheric Ozone, Carbon Monoxide, Europe