Preliminary Validation of Total Water Vapor Column Production of Scanning Microwave Radiometer Onboard HY-2 Satellite

The scanning microwave radiometer (RM) was launched on August 16, 2011, onboard HY-2 satellite. As the one of primary parameters retrieved from HY-2 RM, the sixmonth long from Jan to Jun 2012 global total water vapor column (WV) obtained from HY-2 scanning microwave radiometer were preliminarily validated using other operational spaceborne radiometer observations. The gridded water vapor productions of Special Sensor Microwave Imager (SSM/I) were seen as “true data” in this inter-comparison. For the global scale, the bias and RMS difference of the dataset of these space-borne collocated WV observations was respectively -0.24 mm and 1.19 mm during this six-month period. With analysis of global map of mean difference of the collocation between HY-2 RM and SSM/I, the map of bias distribution appeared that there were a positive deviation about 1mm in the tropic ocean where the precipitation and humidity were in relative high level, a negative deviation in the coastal and near-shore regions. The results suggested that accuracy of retrieval algorithm for HY-2 WV productions obviously depends on latitude. There were potential and room for improvement of retrieval accuracy of WV, for correcting overestimation of WV in the tropic sea and underestimation in the inshore regions relative to SSM/I observations.