ESTIMATION OF CLOUD LIQUID WATER OVER THE HUBEX AREA USING THE TRMM MICROWAVE IMAGER

The ability of the Tropical Rainfall Measuring Mission Microwave Imager(TRMM/TMI) for cloud liquid water(CLW) retrieval has been demonstrated in this study.Due to the great sensitivity of the TMI 85.5 GHz channels to CLW,the liquid water path(LWP) of nonprecipitating clouds over land can be successfully estimated using the VDISORT model based on the iteration steps.Both the vertical-polarized 85.5 GHz single-channel method and the polarization-difference of 85.5 GHz method were applied to the LWP estimates over land regions during the Huaihe River Basin Energy and Water Cycle Experiment(HUBEX) in China.Theretrieval results show reasonable agreement with the ground-based microwave radiometer measurements.When the surface emissivity or skin temperature is difficult to be made sure,the polarization-difference method shows advantages of providing estimates of LWP especially for low clouds because of its extremely insensitiveness to the surface skin temperature.