Impact of GMI rain rate on East Asian Multi-Satellite Integrated Precipitation Estimates

Abstract:

During the last three years, the East Asian Multi-Satellite Integrated Precipitation (EMSIP) was developed at China Meteorological Administration (CMA) National Meteorological Information Center (NMIC), partially through cooperation with NOAA/CPC. IR TBB data from the FY-2 Geostationary satellite and PMW rain rate retrievals from FY-3B, TRMM, NOAA-18/19, METOP-A/B, and DMSP-F16/17/18 were integrated to produce high-resolution satellite precipitation estimates over East Asia. While the current version of the product relies on retrievals from TMI to inter-calibrate inputs from other platforms, work is underway to improve the quality of EMSIP using retrievals from the GMI.

 

As an important step to infuse the GMI into our integration system, a comprehensive evaluation is performed for the precipitation retrievals from the GMI and the 8 other above mentioned PMW sensors with an emphasis on their performance on detecting and quantifying light rain and snowfall. PMW retrievals are compared against in situ measurements from a dense network of automatic rain gauges over China for a cold season month (January 2015). Impacts of infusing GMI precipitation retrievals into our integrated estimates are examined. Results showed improved capacity of the current version GMI retrievals in capturing light rain and snowfall than other sensors for the test period over China. The FAR score, however, is about the same as that for the TMI’s. Partially due to the limited test period, only minor improvements are observed in the EMSIP through infusing GMI. Compared with CMORPH, the correlation of EMSIP and the GMI infused EMSIP is still a little lower over whole china, but sometimes over Tibet Plateau the correlation of EMSIP+GMI is higher than EMSIP and CMORPH.