THE RETRIEVALOF RAINFALL INTENSITY AND VERTICAL STRUCTURE OF HYDROMETERS USING GPROF ALGORITHM

The framework of GPROF algorithm, used as operational rainfall retrieval algorithm for TMI by NASA is introduced. GPROF algorithm is used to retrieve the rainfall intensity and vertical structure of hydrometers for some rainfall cases, including rain cases of Changde area in the summer of 2002 and a case of Utor typhoon attacking Hongkong on 5 July 2001, in terms of TMI 1B11 data. Comparison of GPROF algorithm retrievals with ground-based radar shows that GPROF algorithm retrievals can retrieve rain intensity well and indicate vertical structure of hydrometers mainly. As far as retrieved rain area, it is better for convective precipitation type than stratified precipitation type. Namely, GPROF algorithm can describe no-raining information better than infrared method especially for convective rainfall but it would leave some stratified precipitation areas out. Similarly, Comparison of GPROF algorithm retrievals with PR 2A25 products on ocean show that the results of GPROF algorithm can catch major rain information of typhoon and show that the results of GPROF algorithm can catch major rain information of typhoon and indicate vertical structure of hydrometers mainly. At same time, the retrieved latent heat can give some thermodynamic characters of typhoon, which ulteriorly help to understand climatic change and general circulation on earth. If an improvement of GPROF algorithm is made according to the precipitation characters of China, such as building a cloud-radiation database using the realistic profiles from measurement of models, considering it is a global algorithm, the precision of retrieval over China may be improved。