全球IMERG卫星反演和ERA5陆面再分析降水在四川地区的适用性研究OACSTPCD

Using precipitation observation data from China Meteorological Administration ground stations from 2019 to 2020,six quantitative evaluation indicators including correlation coefficients(CCs),mean bias errors(MBEs),root mean square errors(RMSEs),probability of detections(PODs),false alarm rates(FARs),and critical success indices(CSIs)were used to analyze the accuracy and regional applicability of the IMERG multi-satellite remote sensing retrieval of the Global New Generation Global Precipitation Measurement Program(GPM)and the European Centre for Medium-Range Weather Forecasts(ECMWF)Fifth Generation Land Surface Reanal-ysis(ERA5L)precipitation products in Sichuan region,China.The results show that the two products have a strong precipitation zone on the eastern side of the western Sichuan Plateau,roughly distributed in a quasi north-south direction,and that ERA5L can capture heavy precipitation centers more accurately compared to IMERG.The consistency between station observations within the basin is better than in the surrounding mountainous areas.The precipitation of IMERG and ERA5L was 15.2%and 33.3%,respectively,higher than that observed by the sta-tion,respectively.The two products have a relatively high ability to capture precipitation events in the western Si-chuan Plateau,with low FAR.From the perspective of time test statistical indicators,the trends and magnitude changes observed by the two products and stations are basically consistent,with relatively high relative station ob-servations being the main trend.Compared to IMERG,ERA5L has a high CC with site observations,a high POD,a high CSI,and a low deviation,but a relatively high FAR.Overall,both IMERG and ERA5L precipitation prod-ucts have shown certain potential for application in Sichuan province,but there are significant differences in accura-cy under different precipitation intensities and terrain conditions,requiring product correction.