Evaluation of Snowfall Retrieval Performance of GPM Constellation Radiometers Relative to Spaceborne Radars

Several current and former ESSIC/CISESS scientists are co-authors on a new paper in Journal of Hydrometeorology titled “Evaluation of Snowfall Retrieval Performance of GPM Constellation Radiometers Relative to Spaceborne Radars”. Former ESSIC scientist Yalei You was first author on the paper. Current ESSIC/CISESS scientists on the paper are Veljko Petkovic, Lisa Milani, John Yang, and Guojun Gu.

 

This study assesses the level-2 snowfall retrieval results from 11 passive microwave radiometers generated by the Version 5 Goddard profiling algorithm (GPROF) relative to two spaceborne radars: CloudSat Cloud Profiling Radar (CPR) and Global Precipitation Measurement (GPM) Ku-band Precipitation Radar (KuPR). These 11 radiometers include six conical scanning radiometers (Advanced Microwave Scanning Radiometer for the Earth Observing System [AMSRE], its successor sensor-AMSR2, GPM Microwave Imager [GMI], and three Special Sensor Microwave Imager/Sounder [SSMIS]) and five cross-track scanning radiometers (Advanced Technology Microwave Sounder [ATMS] and four Microwave Humidity Sounder [MHS]).

 

Results show that over ocean conical scanning radiometers have better detection and intensity estimation skills than cross-track sensors, likely due to the availability and usage of the low frequency channels (e.g., 19 and 37 GHz). Over land, AMSRE and AMSR2 have noticeably worse performance than other sensors, primarily due to the lack of higher than 89 GHz channels (e.g., 150, 166, and 183 GHz). Over both land and ocean, all 11 sensors severely underestimate the snowfall intensity, which propagates to the widely used level 3 precipitation product (i.e., Integrated Multi-satellite Retrievals for GPM [IMERG]). These conclusions hold regardless of using either KuPR or CPR as the reference, though the statistical metrics vary quantitatively. The conclusions drawn from these comparisons apply solely to the GPROF Version 5 algorithm.

 

To access the article, click here: “Evaluation of Snowfall Retrieval Performance of GPM Constellation Radiometers Relative to Spaceborne Radars”.