New Insights into the Convective System Characteristics Over the Indian Summer Monsoon Region Using Space-Based Passive and Active Remote Sensing Techniques†

Abstract

The characteristics of convective systems over the Indian summer monsoon (ISM) region derived by using a unique combination of four satellites METEOSAT, TRMM, COSMIC and CloudSat comprising of both active and passive remote sensing sensors are discussed for the first time. Six years of observations during ISM brought out the preferential geographical regions and time for formation of shallow, deep, and very deep convective systems. It has been observed that shallow, deep, and very deep convective clouds are abundant over ISM region and their distributions show a relatively high frequency of occurrence over the Head Bay of Bengal as compared to other regions. The mean vertical structure of clouds are also been studied using CloudSat observations over several latitudinal belts. The time of maximum occurrence of convective type cloud systems are also quantified using the present observations. The analysis suggests that the deep and very deep convective cloud systems peak during late afternoon hours over many parts of the Indian landmass with few exceptions such as over foothills of the Himalayas, where it peaks during the early morning hours. The three-dimensional structures of convective systems are also discussed. The significance of the present results lie in providing new insights into the characteristics of convective systems by investigating CAPE, clouds, and precipitation, which in turn play a vital role in understanding the internal dynamics of ISM.