A METHOD FOR COMBINED PASSIVE-ACTIVE MICROWAVE RETRIEVALS OF CLOUD AND PRECIPITATION PROFILES

Three-dimensional tropical squall-line simulations from the Goddard cu mulus ensemble (GCE) model are used as input to radiative computations of upwelling microwave brightness temperatures and radar reflectiviti es at selected microwave sensor frequencies. These cloud/radiative cal culations form the basis of a physical cloud/precipitation profile ret rieval method that yields estimates of the expected values of the hydr ometeor water contents. Application of the retrieval method to simulat ed nadir-view observations of the aircraft-borne Advanced Microwave Pr ecipitation Radiometer (AMPR) and NASA ER-2 Doppler radar (EDOP) produ ce random errors of 23%, 19%, and 53% in instantaneous estimates of in tegrated precipitating liquid, integrated precipitating ice, and surfa ce rain rate, respectively. On 5 October 1993, during the Convection a nd Atmospheric Moisture Experiment (CAMEX), the AMPR and EDOP were use d to observe convective systems in the vicinity of the Florida peninsu la. Although the AMPR data alone could be used to retrieve cloud and p recipitation vertical profiles over the ocean, retrievals of high-reso lution vertical precipitation structure and profile information over l and required the combination of AMPR and EDOP observations. No validat ion data are available for this study; however, the retrieved precipit ation distributions from the convective systems are compatible with li mited radar climatologies of such systems, as well as being radiometri cally consistent with both the AMPR and EDOP observations. In the futu re, the retrieval method will be adapted to the passive and active mic rowave measurements from the Tropical Rainfall Measuring Mission (TRMM ) satellite sensors.