Spring diurnal cycle of clouds over Tibetan Plateau: Global cloud-resolving simulations and satellite observations

Abstract

Thermal forcing of the Tibetan Plateau (TP) has large impacts on the Asian summer monsoon. In this study, we statistically analyzed the outputs from the global cloud-resolving model, NICAM (Nonhydrostatic ICosahedral Atmospheric Model). In order to investigate the convective activities, two brightness temperature datasets were compared, one derived from the satellite observation and another derived from the model. The model well simulated the spatio-temporal variations of convective clouds in April 2004. The diurnal cycle of clouds was better represented in NICAM, which shows only few-hour phase difference, than that in the reanalysis data. Three experiments changing horizontal resolution revealed that the higher resolution run conducts better representation of the diurnal cycle, especially on the nighttime disappearance of the high clouds. These results indicate that the global cloud-resolving model will improve the seasonal prediction of the Asian summer monsoon through better description on the thermal forcing of the Tibetan Plateau. Copyright 2007 by the American Geophysical Union.