FY-3C/MWHTS资料反演陆地晴空大气温湿廓线  

Retrieval of clear sky temperature and humidity profiles over land using measurements of FY-3C/MWHTS

作　　者：贺秋瑞[1,2] 王振占[1] 何杰颖[1] 

机构地区：[1]中国科学院国家空间科学中心微波遥感重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《遥感学报》2017年第1期27-39,共13页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家高技术研究发展计划(863计划)(编号:2015AA8126027);国家空间科学中心重点培育课题(编号:Y62112f37s)~~

摘　　要：针对风云三号C星微波湿温探测仪(FY-3C/MWHTS)的陆地晴空观测资料,建立了一维变分反演系统,对大气的温湿廓线进行反演。为了更好地描述温湿廓线的相关性,同时减小温度和湿度在反演过程中相互之间的误差传递,提出了使用背景协方差矩阵的联合矩阵和单独矩阵进行组合反演的方法。对于MWHTS模拟亮温和观测亮温之间的偏差,使用逐扫描点的统计回归方法进行校正。选择中国部分陆地区域的晴空观测亮温进行温湿廓线的反演,并利用欧洲中期天气预报中心(ECMWF)再分析数据、美国国家环境预报中心(NCEP)分析数据以及无线电探空观测(RAOB)数据对反演结果进行验证,温湿廓线的反演结果与ECMWF再分析数据验证的最大均方根误差分别是2.59 K和11.87%,与NCEP分析数据验证的最大均方根误差分别是1.88 K和21.50%,与RAOB数据验证的最大均方根误差分别是3.43 K和25.48%,验证结果表明了反演结果的可靠性。另外与国外同类载荷AMSU观测亮温的物理方法和统计方法反演精度进行了对比,结果表明:MWHTS具有较强的湿度廓线以及高空温度廓线的探测能力,且针对MWHTS的观测亮温建立的一维变分反演系统具有较高的反演精度。与NCEP 6小时预报廓线的验证结果表明:反演的湿度廓线可以提高预报廓线的精度。Land surface emissivity has a significant effect on the atmospheric temperature and humidity sounding from space. Given the complicated land surface, the calculated emissivity is generally with low accuracy. A one-dimensional variational retrieval system was built using measurements of microwave humidity and temperature sounder onboard the Fengyun-3C satellite （FY-3C/MWHTS）to improve re- trieval accuracy and to reduce the computation complexity in retrieving atmospheric temperature and humidity profiles over land under clear sky. By analyzing the a priori information affecting the accuracy of inversion, a hybrid retrieval approach based on united and individual matrices of background covariance is proposed. The method established a better correlation relationship between temperature and humidity profiles, reduced the error propagation of the retrieval temperature and humidity, and prevented the complicated land emissivity calculations according to different surface types. From the correlation between the observed values from FY-3C/MWHTS and those simulated by the for- ward radiative transfer model, a statistical regression method was also adapted in pixel-by-pixel correction procedure to correct the bias between observed and simulated values. This retrieval system obtains temperature and humidity profiles over a part of China＇s land under clear sky and validates the retrieval results with respect to the European Centre for Medium-Range Weather Forecasts（ECMWF） reanalysis data, National Centers for Environ- mental Prediction（NCEP） analysis data, and Radiosonde Observation（RAOB） data. With respect to the ECMWF reanalyzed data, the max- imum root mean square errors of the resulting temperature and relative humidity are 2.59 K and 11.87%, respectively. With respect to the NCEP analyzed data, the maximum root mean square errors of the resulting temperature and relative humidity are 1.88 K and 21.50%, re- spectively. With respect to the RAOB data, the maximum root mean square errors of the resulting

关 键 词：MWHTS 一维变分反演 温湿廓线 逐扫描点校正 预报廓线 

分 类 号：P407.7[天文地球—大气科学及气象学]