GPM-DPR observed microphysical characteristics of the Arabian Sea tropical cyclone

The precipitation characteristics of tropical cyclones (TCs) formed between 2014-2021 over the Arabian Sea during the onset phase of monsoon and after the monsoon (post-monsoon) seasons have been investigated through the space-borne dual-frequency precipitation radar of the Global Precipitation Measurement (GPM-DPR) satellite level 2, V07 observation. In a cloud that is producing precipitation, the two-dimensional frequency distribution of the liquid water content (LWC; g/m²) and non-liquid water content (IWC; g/m²) exhibits a clear seasonal and cloud-type dependence. For the precipitating cloud of stratiform origin of TCs in the monsoon and post-monsoon seasons, a significant part of rain droplets is present in the LWC limit of 0-800 g/m² and the IWC limit of 0-350 g/m². In contrast to the stratiform precipitation associated with the TCs, the LWC quantity is additionally more, and IWC is less for the convective origin precipitating cloud. In the monsoon and post-monsoon season, the mean values of the mass-weighted mean diameter, D_m (mm), are 1.29 (1.47) mm and 1.27 (1.31) mm, respectively, for the stratiform (convective) cyclonic cloud. It is noticed that when the value of D_m increases, the normalised intercept parameters (Nw) decrease, regardless of the season and cloud type related to the TCs. While stratiform precipitation contains a considerably high concentration of smaller-sized rain droplets during both seasons, the number concentration of bigger rain droplets is significantly high during convective precipitation. From the contoured frequency with altitude diagram (CFAD) plots for D_m and Z_e for the cyclonic cloud in both seasons, we observe a large concentration of ice and supercooled liquid particles available above the melting layer and a significant concentration of rain droplets in liquid state present below the melting layer. We derived the contribution of the different microphysical processes (break-up, size-sorting, collision-coalescence, and evaporation processes) in the rain droplets formation below the melting layer. It is found that the process of collision-coalescence is predominating microphysical process for convective precipitation. The break-up process is a primary microphysical process in the precipitating cloud of stratiform origin.