Retrieval of the Vertical Rainfall Structure from the Madras Imager Data of the Megha-Tropiques Satellite

A physically based algorithm for the retrieval of vertical cloud and rain structure from the MADRAS imager data of Megha-Tropiques is developed. A communitydeveloped meso-scale numerical weather simulation software, WRF, has been used for simulation of thermodynamic, cloud and rain profiles for a cyclone case. The WRF simulated profiles in conjunction with two of the rain-measuring instruments on-board the TRMM satellite, the TMI and the TRMM PR, are used as a priori cloud and rain profiles database. These profiles were input to an in-house radiative transfer code. Brightness temperatures at MADRAS imager frequencies were simulated to complete the generation of a priori database. Brightness temperatures were also simulated for TMI channels for comparison, wherever possible.

Sample MADRAS data were downloaded and retrievals were performed for the MADRAS channels. The retrieved wind speed, column-integrated liquid water and surface rain rate were compared against the Level 2 data of Megha-Tropiques mission. A comparison of daily averaged rain rate with TMI retrievals was also made. The results show that the retrieval algorithm is robust and able to retrieve the vertical cloud and rain structure even in the absence of a radar on-board the Megha-Tropiques.