NPOESS Precipitation Retrievals Using the ATMS Passive Microwave Spectrometer

This letter evaluates the ability of the U.S. National Polar-orbiting Operational Environmental Satellite System 22-channel Advanced Technology Microwave Sounder (ATMS) to retrieve surface precipitation rates (millimeters per hour); water path estimates for rain, snow, and graupel (millimeters); and peak vertical wind (convective strength, meters per second). Simulated retrieval accuracies for ATMS were compared to those for its predecessor the Advanced Microwave Sounding Unit (AMSU), both of which sample the 23- to 190-GHz spectrum. ATMS retrieves all precipitation parameters up to ~ 25% more accurately than AMSU except for cloud ice and snow water paths, which are comparable. Image sharpening of the ATMS Nyquist-sampled observations below 90 GHz further improves the recovery of small features but amplifies noise so that the benefits are restricted primarily to finely structured convective systems.