Study of Mesoscale Convective System and its Associated Cloud Structure over Indian Region Using Satellite Observations and Model Simulations

Abstract

The present study has discussed the identification of mesoscale convective systems (MCS) events using Cloud top temperatures from Cloud and the Earth�s Radiant Energy System and INSAT 3D imageries over the Indian region. The parameters such as height, areal extent, and vertical depth are considered as the criteria for identifying these intense rain-bearing MCS. High equivalent potential temperature, pronounced warm advection, low-level convergence, and local maximum in relative vorticity is associated with large-scale environments are the key indicators in identifying MCS. A total of five heavy rainfall events associated with MCS are simulated using the Weather Research and forecasting at a horizontal resolution of 3�km with a lead time of up to 96�h. In addition, the performance of two cumulus and four cloud microphysical parameterizations and their optimized combination are investigated for these MCS systems causing heavy rainfall over the region. The Betts�Miller�Janjic�Thompson combination simulated the best results in terms of rainfall, convective available potential energy, vertical updrafts, and reflectivity and its pre-formation environment of MCS. Further, this optimized combination is able to accurately represent the dominant hydrometeors (i.e., rain, graupel and snow), which have played a key role in simulating the MCS. Large-scale forcing such as moisture advection, convergence, relative vorticity, and equivalent potential temperature play a dominant role in the evolution and sustenance of MCS. Finally, a more robust (weaker) intensity MCS is better (poorly) predicted by the model. The findings of this study will further augment our understanding for better prediction of MCS associated with heavy rainfall events over the Indian region. � 2022, Indian Society of Remote Sensing.