The current status of the NOAA/AMSU-based operational precipitation product

NOAA has been generating operational AMSU-based precipitation retrievals since the first AMSU was placed into operation in July 1998. These are generated through a system known as the Microwave Surface and Precipitation Products System (MSPPS). MSPPS is presently operational for NOAA-15, -16, -17 and is undergoing checkout for NOAA-18 (anticipated to be operational during the fall of 2005).

The MSPPS precipitation retrieval algorithm is based upon a physical retrieval scheme that utilizes AMSU-B 89 and 150 (157) GHz measurements to first retrieve ice water path, which is then converted to a precipitation rate. Other MSPPS products (such as snow and ice cover), AMSU radiances (at 23, 31, 50 and 54 GHz) and ancillary data (NWP model forecast fields) are used in the retrieval scheme, primarily for surface type identification. Since the original version of this algorithm was implemented in 1998, several modifications and improvements have been developed to improve the precipitation rate retrievals. This includes a two-stream approximation for the microwave radiances, utilization of the 183 GHz water vapor bands to identify deep convection, and the application of 50 GHz sounding channels to identify falling snow over land.

This paper will present the current status of the MSPPS precipitation products, discuss its performance on both swath and time-average scales, and identify future improvements to the algorithm.