Cloud microphysical properties as revealed by the CAIPEEX and satellite observations and evaluation of a cloud system resolving model simulation of contrasting large scale environments

Clouds add the largest uncertainty in the current general circulation model. The numerical representation of clouds in the models can be improved by a better understanding of cloud processes in the tropics. This can be accomplished provided there is observational data at a good spatio-temporal resolution to capture the cloud scale processes. One such issue is addressed in the "Cloud-Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX)" over the Indian region during May-Sep, 2009. The objective of this paper is to bring out the microphysics of clouds during two contrasting days of Indian Summer Monsoon (ISM) based on the CAIPEEX data as well as on satellite observations over the region of Central India (Cl). The paper also intends to study as to what extent the Weather Research and Forecasting (WRF) Model simulation at cloud system resolving grid (27-9-3 km) could capture the observed cloud types and properties. The rainfall observations on July 15 and August 18,2009 suggest, respectively, an active and suppressed monsoon convection over central India. Upon analysis, it has been found that during an active or break phase of monsoon, significant heterogeneity exists in cloud distribution and types. The WRF simulation is able to capture some of the observed features of the cloud but could not simulate the middle and low level clouds. Thus a modification in cloud parameterization schemes may be helpful to improve the model biases, which in turn could improve the forecast of cloud life cycle vis-a-vis precipitation. (C) 2011 Elsevier Ltd. All rights reserved.