Statistical Analyses of Satellite Cloud Object Data from CERES. Part III: Comparison with Cloud-Resolving Model Simulations of Tropical Convective Clouds

The present study evaluates the ability of a cloud-resolving model (CRM) to simulate the physical properties of tropical deep convective cloud objects identified from a Clouds ,and the Earth’s Radiant Energy System (CERES) data product. The emphasis of this study is the compar- isons among the small-, medium- and large-size categories of cloud objects observed during March 1998 and between the large-size categories of cloud objects observed during March 1998 (strong El Niño) and March 2000 (weak La Niña). Results from the CRM simulations are ana- lyzed in a way ,that is consistent with the CERES retrieval algorithm and they are averaged to match the scale of the CERES satellite footprints. Cloud physical properties are analyzed in terms of their summary,histograms for each category. Itis found that there is a general agreement in the overall shapes of all cloud physical properties between,the simulated and,observed distributions. Each cloud physical property pro- duced by the CRM also exhibits different degrees of disagreement with observations over differ- ent ranges of the ,property. The simulated cloud tops are generally too high and cloud top temperatures are too low except for the large-size category of March 1998. The probability densi- ties of the simulated top-of-the-atmosphere (TOA) albedos for all four categories are underesti- mated for high albedos, while those of cloud optical depth are overestimated at its lowest bin. These disagreements are mainly related to uncertainties in the cloud microphysics parameteriza-