Microwave radiometric observation of a waterspout over coastal Arabian Sea

Abstract

This letter discusses the background thermodynamic conditions of a convective cloud during the occurrence of a waterspout. This study is conducted using a very unique experimental observation of a ground-based multifrequency microwave radiometer which was set to scan the atmosphere in seven elevation angles. The spatio-temporal variations of the cloud microphysical parameters during the evolution of a multicell convective cumulus system are studied. Humidity and temperature anomalies deduced from the radiometric observation could clearly explain the convective processes like the formation of an intense updraft of moist air, convective heating due to large latent heat energy release, and cooling of the lower atmosphere below 2-km altitude by the downdrafting dry air. The measurements from collocated IR radiometer, surface met sensors, and calculated CAPE showed the formation of an intense convection in a humid warm atmosphere over a shallow warm ocean (conducive to formation of a waterspout). Studies on the evolution of cloud parameters during the life cycle of convective precipitation are of great interest in weather forecasting.