Atmospheric latent heating distributions in the tropics derived from satellite passive microwave radiometer measurements

A method for the remote sensing of three-dimensional latent heating distrib utions in precipitating tropical weather systems from satellite passive mic rowave observations is presented. In this method, cloud model simulated hyd rometeor/latent heating vertical profiles that have radiative characteristi cs consistent with a given set of multispectral microwave radiometric obser vations are composited to create a best estimate of the observed profile. A n estimate of the areal coverage of convective precipitation within the rad iometer footprint is used as an additional constraint on the contributing m odel profiles. This constraint leads to more definitive retrieved profiles of precipitation and latent heating in synthetic data tests. The remote sensing method is applied to Special Sensor Microwave/lmager (SS M/I) observations of tropical systems that occurred during the TOGA COARE I ntensive Observing Period, and to observations of Hurricane Andrew (1992). Although instantaneous estimates of rain rates are high-biased with respect to coincident radar rain estimates, precipitation patterns are reasonably correlated with radar patterns, and composite rain rate and latent heating profiles show respectable agreement with estimates from forecast models and heat and moisture budget calculations. Uncertainties in the remote sensing estimates of precipitation/latent heating may be partly attributed to the relatively low spatial resolution of the SSM/I and a lack of microwave sens itivity to tenuous anvil cloud, for which upper-tropospheric latent healing rates may be significant. Estimated latent heating distributions in Hurric ane Andrew exhibit an upper-level heating maximum that strengthens as the s torm undergoes a period of intensification.