Recent improvements to the Multi-Satellite Precipitation Analysis (MPA) using AMSR and AMSU data

The Multi-Satellite Precipitation Analysis (MPA), a quasi-global, three-hourly data set, uses TRMM observations (radar and passive microwave) to calibrate polar-orbiting microwave observations from SSM/I and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the MPA. Rain gauge information is used to help constrain the satellite-based estimates over land.

Recently, observations from the AMSR and AMSU instruments have been incorporated into the analysis. Like the SSM/I and IR, these data are calibrated by TRMM observations. One obvious benefit of adding these instruments is a more representative sampling of the diurnal cycle of precipitation with high quality microwave estimates. Validation of the MPA before and after the addition of AMSR and AMSU data will be examined.

The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) in 2004. The real-time version of this merged product has been produced over the last two years and is available through links at the U.S. TRMM web site (trmm.gsfc.nasa.gov) or directly from ftp://aeolus.nascom.nasa.gov/ pub/merged at 0.25-degree latitude-longitude resolution over the latitude range 50°N-50°S.