The objective of the talk is to document the evolution of the LMD GCM in terms of cloud and radiation, starting from the official AMIP experiment.
The parameterization of clouds in the LMD GCM has evolved continuously, in order to improve the model climatology, but also following the need to take into account new concerns and new physical processes. One example is the need to better understand the indirect effects of aerosols in climate change scenarios. An important development of the model parameterizations has therefore been to introduce a representation of the cloud microphysics which affects the cloud precipitation. The treatment of convective clouds and convective cloud water has also been the subject of various studies. These modifications have been documented by the comparison to various data sets: ERBE radiative budgets, but also ISCCP analysis, or ground-based cloud observations. The methodological aspects of these comparisons, and the importance of cloud subgrid-scale properties will be reviewed. Finally the results of the more recent higher-resolution versions of the model will also be described.