FY4A与GPM反演降水产品在中国内地的误差解析  

Error Evaluation of FY4A and GPM Satellite Precipitation Estimates over Chinese Mainland

作　　者：李季 雍斌 吴昊[1,2] Ji LI;Bin YONG;Hao WU(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098 [2]河海大学水文水资源学院,江苏南京210098

出　　处：《遥感技术与应用》2024年第5期1223-1236,共14页Remote Sensing Technology and Application

基　　金：多尺度流域水资源和水利设施遥感监测应用示范(SQ2021YFB3900015)。

摘　　要：高时空分辨率的卫星降水数据对于近实时降水监测和实时水文预报非常重要。以中国内地为研究区,从小时尺度综合分析4种近实时卫星降水产品,包括基于风云卫星的REGC和DISK、基于GPM的IMERG-Early和GSMaP-NRT,揭示降水反演误差与4个关键影响因子(季节、气候区、降雨强度、地形)之间的关系。评估结果如下:在小时尺度上,IMERG-Early在中国内地的表现最好,具有最高的相关系数(CC=0.44)和最低的均方根误差(RMSE=0.97 mm/h);其次是GSMaPNRT,在湿润区具有最低的误报率;REGC和DISK仅在湿润区南部和东部具有令人满意的相关系数和分类统计指数。在季节尺度上,所有卫星降水产品在夏季的准确性最好,在冬季的性能最差。在降水强度方面,除IMERG-Early外,其他3种卫星降水产品更倾向于高估无雨(0~0.2 mm/h)事件的概率密度;REGC在小雨(0.2~0.6 mm/h)事件下的表现最好,具有最低的偏差;与其他卫星降水产品在暴雨下(>5 mm/h)的表现相比,DISK对暴雨的低估程度更小,得益于其短延时特性,DISK在暴雨监测和洪水预报中拥有更大的应用潜力。IMERG-Early和GSMaP-NRT在低海拔地区的表现都优于高海拔地区,REGC和DISK的性能在高程大于3 000 m后显著增加。相关的评估结果将为风云产品的算法改进提供一些反馈,并使数据用户能够进一步了解风云降水量估计的误差特征和潜在缺陷。Satellite precipitation estimates with high spatial and temporal resolutions play an important role in near-real-time precipitation monitoring and real-time hydrological forecasting.Four near-real-time satellite precipitation products,including the Fengyun-based(REGC and DISK)and the GPM-based(IMERG-Early and GSMaP-NRT),were synthesized and analyzed at hourly scales over the Chinese mainland.And the relationships between precipitation inversion errors and four key influencing factors(season,climate zone,rainfall intensity,and topography)were revealed.Results show that:IMERG-Early has the best overall performance with the highest correlation coefficient(CC=0.44)and the lowest root mean square error(RMSE=0.97 mm/h)over the Chinese mainland compared with hourly-scale ground measurements;followed by GSMaP-NRT which performs better and has the lowest false alarm rate in the humid region;while REGC and DISK have satisfactory correlation coefficients and classification statistical indices only in the southern and eastern parts of the humid region.All satellite precipitation estimates performed best in summer and showed poor accuracy in winter.The precipitation intensity analysis shows that the three satellite precipitation products,except IMERG-Early,tend to overestimate the occurrence of rainless events;REGC underestimates the occurrence of light rainfall(0.2~0.6 mm/h)events,but has better agreement with ground measurements and has a lower bias than the other satellite precipitation products.Moreover,DISK has a lower bias in the case of heavy rainfall(>5 mm/h).Both satellite precipitation products of the GPM series perform better at low altitudes than at high altitudes,while the performance of both precipitation products of FY4A increases significantly at high altitudes(DEM>3000 m).The evaluation results related here will provide some valuable feedback to the algorithm developers of the Fengyun products and enable data users to further understand the error characteristics and potential shortcomings of the Fenyun precip

关 键 词：FY4A GPM 近实时卫星降水 精度评估 误差解析 中国内地 

分 类 号：P412[天文地球—大气科学及气象学]