Retrieval of Cloud Ice Water Path from Special Sensor Microwave Imager/Sounder (SSMIS)

The Special Sensor Microwave Imager/Sounder (SSMIS) aboard the Defense Meteorological Satellite Program (DMSP) F-16 spacecraft measures the Earth-emitted radiation at frequencies from 19 to 183 GHz. From its highest frequencies, cloud microphysical parameters can be observed at a spatial resolution of 15 km. In this study, a two-stream radiative transfer theory is simplified for microwave applications as a three-parameters algorithm and then used to retrieve the ice cloud water path (IWP) and ice particle effective diameter (De). Since SSMIS is a conically-scanning instrument, the retrieved IWP is less dependent on scan position and is an ideal product for imaging atmospheric ice-phase clouds related to precipitation. Thus, IWP is also used to estimate surface rainfall rate through the same relationship derived previously and used in AMSU-B and MHS applications.