Diurnal cycle of rainfall over Central Africa simulated by RegCM

Abstract

This study evaluates the performance of the Regional Climate Model (RegCM4) at 25 km horizontal resolution in capturing the diurnal cycle of precipitation over Central Africa. The Tropical Rainfall Measuring Mission (TRMM) 0.25° × 0.25° rain-rates are used to evaluate RegCM4 simulation between 1998 and 2009. It is found a good agreement between the spatial distribution of the simulated and observed diurnal cycle of rainfall over the continent. Results indicate that the regional model exhibits a dry bias over the ocean. The minimum of the simulated diurnal cycle of precipitation is too early over land and the amplitude is too weak over ocean. The major similarities in the phase are found over the continental regions, however, substantial differences are seen over the ocean. The propagating diurnal cycle of precipitation, evident in TRMM, is well captured by the model.