Spatiotemporal Variations of Microwave Land Surface Emissivity(MLSE)over China Derived from Four-Year Recalibrated Fengyun 3B MWRI Data  

作　　者：Rui LI Jiheng HU Shengli WU Peng ZHANG Husi LETU Yu WANG Xuewen WANG Yuyun FU Renjun ZHOU Ling SUN 

机构地区：[1]School of Earth and Space Sciences,Comparative Planetary Excellence Innovation Center,Chinese Academy of Sciences,University of Science and Technology of China,Hefei 230026,China [2]State Key Laboratory of Fire Science,University of Science and Technology of China,Hefei 230026,China [3]National Satellite Meteorological Center of China Meteorological Administration,Beijing 100044,China [4]State Key Laboratory of Remote Sensing Science,The Aerospace Information Research Institute,Chinese Academy of Sciences(CAS),Beijing 100101,China [5]Green Earth Research Inc.,Slingerlands,New York 12259,USA

出　　处：《Advances in Atmospheric Sciences》2022年第9期1536-1560,共25页大气科学进展（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.41830104,41661144007,41675022,and 41375148);Research and Development Program of China(Grant No.2017YFC1501402);the Jiangsu Provincial 2011 Program(Col-laborative Innovation Center of Climate Change).

摘　　要：Microwave Land Surface Emissivity(MLSE)over China under both clear and cloudy sky conditions was retrieved using measurements of recalibrated microwave brightness temperatures(Tbs)from Fengyun-3B Microwave Radiation Imager(FY-3B MWRI),combined with cloud properties derived from Himawari-8 Advanced Himawari Imager(AHI)observations.The contributions from cloud particles and atmospheric gases to the upwelling Tbs at the top of atmosphere were calculated and removed in radiative transfer.The MLSEs at horizontal polarizations at 10.65,18.7,and 36.5 GHz during 7 July 2015 to 30 June 2019 over China showed high values in the southeast vegetated area and low values in the northwest barren,or sparsely vegetated,area.The maximum values were found in the belt area of the Qinling-Taihang Mountains and the eastern edge of the Qinghai-Tibet Plateau,which is highly consistent with MLSEs derived from AMSR-E.It demonstrates that the measurements of FY-3B MWRI Tbs,including its calibration and validation,are reliable,and the retrieval algorithm developed in this study works well.Seasonal variations of MLSE in China are mainly driven by the combined effects of vegetation,rainfall,and snow cover.In tropical and southern forest regions,the seasonal variation of MLSE is small due to the enhancement from vegetation and the suppression from rainfall.In the boreal area,snow causes a significant decrease of MLSE at 36.5 GHz in winter.Meanwhile,the MLSE at lower frequencies experiences less suppression.In the desert region in Xinjiang,increases of MLSEs at all frequencies are observed with increasing snow cover.

关 键 词：satellite remote sensing microwave surface emissivity Fengyun-3B MWRI Himawari-8 AHI 

分 类 号：P407[天文地球—大气科学及气象学]