On the microwave measurement of precipitation in tropics

The difference between the brightness temperature structure over a typical tropical rain system and that of the midlatitude thunderstorms is examined. It is also determined how the brightness temperature and the rain rate relationship at the microwave frequencies deviates from that in the thunderstorms. It is shown, in particular, that the theoretical brightness temperature and rain rate relationship at 19.35 GHz provides good estimates of the surface rain rates for either convective or stratiform precipitation, but the relationship at 37 and 85.5 GHz may result in a significant overestimation of surface rain rate, especially for stratiform precipitation.