星载雷达降水反演算法敏感性分析  

Spaceborne radar-based precipitation retrieval:Sensitivity analysis

作　　者：吴琼 尹红刚 陈林[1] 商建 谷松岩[1] 卢乃锰[1] WU Qiong;YIN Honggang;CHEN Lin;SHANG Jian;GU Songyan;LU Naimeng(Innovation Center for FengYun Meteorological Satellite(FYSIC),Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites,National Satellite Meteorological Centre(National Space Weather Monitoring and Early Warning Centre),China Meteorological Administration,Beijing 100081,China)

机构地区：[1]许健民气象卫星创新中心,中国气象局中国遥感卫星辐射测量和定标重点开放实验室/国家卫星气象中心(国家空间天气监测预警中心),北京100081

出　　处：《气象学报》2024年第2期236-246,共11页Acta Meteorologica Sinica

基　　金：国家重点研发计划(2022YFB3902603);国家自然科学基金(41905063、42005109);中国气象局青年创新团队项目(CMA2023QN12)。

摘　　要：以全球降水测量卫星(GPM)Ku PR的实测资料作为代理数据,评估了风云三号G星降水测量雷达(FY-3G PMR)原型算法的精度。在此基础上,对降水率和质量加权平均直径(R-D_(m))初始关系、降水相态以及不均匀波束充塞效应(NUBF)订正因子(param NUBF)进行了降水反演的敏感性分析。首先对调层云和对流云的R-D_(m)初始关系,比较初值调整前后滴谱廓线、雷达反射率因子廓线及降水率廓线的变化;其次设计敏感性试验,分析相态的误判对降水反演精度的影响;最后通过设置不同的param NUBF,评估param NUBF对降水反演的敏感性。结果表明,FY-3G PMR原型算法反演的降水结构及强弱分布和GPM Ku PR具有很好的一致性,反演的相对误差小于10%,相关系数大于0.95。敏感性分析显示雷达反射率因子廓线和降水率廓线的反演对R-D_(m)初始关系不敏感,但滴谱廓线的反演对R-D_(m)初始关系比较敏感。0℃亮带层相态误判尤其是混合相态和固态以及混合相态和液态的误判,影响0℃层附近的空中降水反演,但对地面降水反演影响不大。param NUBF作为高敏感性因子,与真值的差异越大降水率廓线反演的误差越大。开展星载雷达降水反演算法的敏感性分析不仅可以加深对降水反演理论和算法的认识,提高降水反演精度,还可以为FY-3G PMR即将开展的外场试验提供设计思路。The accuracy of the FY-3G PMR prototype algorithm is evaluated using the data of GPM KuPR.Based on the result,the R-D_(m)sensitivity of precipitation rate retrieval to initial relation of-,phase,and the correction factor paramNUBF for NUBF is R-D_(m)analyzed.Firstly,the-relation of stratiform and convection are adjusted and the DSD profiles,radar reflectivity factor profiles,and precipitation rate profiles are compared.Secondly,sensitivity experiments are conducted to analyze the impact of phase misjudgment on the accuracy of precipitation rate retrieval.Finally,the sensitivity of paramNUBF to precipitation rate retrieval is evaluated by setting different paramNUBF.The results indicate that the FY-3G PMR prototype algorithm is well consistent with GPM KuPR in the retrieval of precipitation structure and intensity distribution,and the relative error is less than 10%while the correlation coefficient is greater than 0.95.The retrievals of radar reflectivity factor profiles and precipitation rate profiles are not R-D_(m) R-D_(m)sensitive to-,but the retrieved DSD profiles are relatively more sensitive to-.Misjudgment of phase in the bright band layer,especially between mixed phase state and solid or between mixed phase state and liquid state,affects precipitation rate retrieval near the 0 degree layer but has little impact on ground precipitation rate retrieval.ParamNUBF is a highly sensitive factor,and the greater the difference from the true value,the greater the error of the precipitation rate profile.The sensitivity analysis on spaceborne radar precipitation rate retrieval algorithms can not only deepen our understanding of precipitation rate retrieval theories and methods and improve the accuracy of precipitation rate retrieval,but also provide design ideas for the upcoming field experiments of FY-3G PMR.

关 键 词：GPM FY-3G PMR 降水反演 相态 NUBF 敏感性分析 

分 类 号：P412.25[天文地球—大气科学及气象学]