Physical and Microwave Radiative Properties of Precipitating Clouds. Part II: A Parametric 1D Rain-Cloud Model for Use in Microwave Radiative Transfer Simulations

Abstract

A highly simplified, yet meteorologically realistic and flexible, parametric model is described for generating hydrometeor profiles and other environmental properties relevant to microwave radiative transfer calculations in quasi-stratiform rain clouds. With this model, it is possible, via 19 adjustable parameters, to vary cloud and environmental properties, including hydrometeor size distributions and densities, in a continuous, yet self-consistent, fashion and to assess the impact of these changes on computed multichannel microwave brightness radiances. It is also possible to utilize gradient descent methods to find plausible combinations of cloud properties that explain observed multichannel microwave radiances in rain clouds. Potential applications of the above model include 1) gaining insight into effective microphysical properties, for microwave radiative transfer purposes, of actual precipitating cloud systems and 2) accurate extrapolation of observed microwave multichannel radiances in rain clouds to the frequencies and viewing angles of new microwave sensors.