Evaluation of the Long-term Performance of Microwave Radiation Imager Onboard Chinese Fengyun Satellites  

作　　者：Wenying HE Hongbin CHEN Xiang’ao XIA Shengli WU Peng ZHANG 

机构地区：[1]Key Labratory for Middle Atmosphere and Global Environment Observation,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [2]National Satellite Meteorological Center,China Meteorological Administration,Beijing 100081,China

出　　处：《Advances in Atmospheric Sciences》2023年第7期1257-1268,共12页大气科学进展（英文版）

基　　金：supported by the National Key R&D Program of China(Grant No.2022YFF0801301);the National Natural Science Foundation of China(Grant No.41575033)。

摘　　要：Accurate brightness temperature(BT)is a top priority for retrievals of atmospheric and surface parameters.Microwave Radiation Imagers(MWRIs)on Chinese Fengyun-3(FY-3)serial polar-orbiting satellites have been providing abundant BT data since 2008.Much work has been done to evaluate short-term MWRI observations,but the long-term performance of MWRIs remains unclear.In this study,operational MWRI BTs from 2012–19 were carefully examined by using simultaneous Advanced Microwave Scanning Radiometer 2(AMSR2)BTs as the reference.The BT difference between MWRI/FY3B and AMSR2 during 2012–19 increased gradually over time.As compared with MWRI/FY3B BTs over land,those of MWRI/FY3D were much closer to those of AMSR2.The ascending and descending orbit difference for MWRI/FY3D is also much smaller than that for MWRI/FY3B.These results suggested the improvement of MWRI/FY3D over MWRI/FY3B.A substantial BT difference between AMSR2 and MWRI was found over water,especially at the vertical polarization channels.A similar BT difference was found over polar water based on the simultaneous conical overpassing(SCO)method.Radiative transfer model simulations suggested that the substantial BT differences at the vertical polarization channels of MWRI and AMSR2 over water were partly contributed by their difference in the incident angle;however,the underestimation of the operational MWRI BT over water remained a very important issue.Preliminary assessment of the operational and recalibrated MWRI BT demonstrated that MWRI BTs were substantially improved after the recalibration,including the obvious underestimation of the operational MWRI BT at the vertical polarization channels over water was corrected,and the time-dependent biases were reduced.

关 键 词：FY-3 satellites MWRI AMSR2 brightness temperature RECALIBRATION 

分 类 号：P407.7[天文地球—大气科学及气象学]