Performance and Uncertainty Analysis of Precipitation Retrievals Derived from Dual-frequency Precipitation Radar and Microwave Imager onboard GPM over CONUS

Abstract:

The Global Precipitation Measurement (GPM) core satellite was launched on February 27 2014. The core sensors dual-frequency precipitation radar (DPR) and microwave imager (GMI) are the state-of- the-art sensors that observe the precipitation over the globe. The DPR level 2 product provides both precipitation rates and phases. The precipitation phase information can help advance global hydrological cycle modeling, particularly crucial for high-altitude and high latitude regions where solid precipitation is the dominated source of water. The GMI is equipped with 13 different microwave channels, and has four more channels on the 166 GHz of a milli-wave zone (“Window” channel) and 183.31 GHz (water vapor absorption line) band than TRMM Macrowave Imgager (TMI), which has nine channels from 10.65 to 89 GHz. The GMI is expected to improve the estimation accuracy of light rain and snow. Goal of this study is to systematically evaluate the DPR and GMI by using the high resolution (1km/2.5min) NOAA/NSSL Multi-Radar Multi-Sensor System (MRMS/Q3) with recent dual-polarization upgrade over the CONUS from March to Aug. 2014. The system and random errors of DPR and GMI will be analyzed as a function of the precipitation rate and precipitation type (liquid and solid). The timely evaluation is expected to offer insights into performance of the two latest sensors and thus provide useful feedback to the algorithm developers as well as the GPM data users.