摘要
为了探讨ERA5再分析降水数据在中国区的适用性,以全国728个站点的日降水数据为参考,使用Pearson相关系数、均方根误差、平均绝对误差、探测率、误报率以及公正先兆评分分析了ERA5再分析降水数据在不同时间尺度(月、季)、不同气候区、不同海拔梯度下的精度以及ERA5再分析数据对暴雨和干旱事件的刻画能力。结果表明:ERA5降水数据对日降水事件的识别能力在空间和时间上均存在差异,整体来看:在北温带的精度最高;在夏、秋两季较冬、春两季的精度低;海拔>500 m地区的精度低于海拔≤500 m地区的精度。ERA5数据在进行暴雨识别时,与站点观测数据的偏差较大,且阈值越大(即暴雨越强)偏差越大;基于ERA5计算的不同尺度的标准化降水指数的精度不同,其中3个月尺度的标准化降水指数的精度最高。在进行干旱事件的识别时,阈值越低(即干旱越严重)误差越大。本研究可为ERA5降水数据的使用范围和使用方法提供参考,有助于分析相关研究的不确定性。
ERA5 is the latest generation of ECMWF reanalysis product.Its precipitation data can be used to analyze the spatial and temporal characteristics of precipitation,extracting rainstorm and flood events,driving crop models,hydrological models,and land surface models.Studies on the effects of using reanalysis data to drive various models to simulate climate change are becoming more common in the context of climate change.However,as atmospheric reanalysis data,the data quality of ERA5 precipitation data will be affected by the errors of forecast products,observation data,and assimilation methods.The precision of reanalysis data will influence the uncertainty of related study results.As a result,verifying and evaluating the accuracy of reanalysis data is both necessary and urgent.To investigate the applicability of ERA5 precipitation data in China,daily precipitation data from 728 Chinese sites were used as a reference to examine the accuracy of ERA5 reanalysis precipitation data at various time scales(month,quarter),different climate zones and different elevation gradients using the Pearson correlation coefficient(r),root mean square error(RMSE),mean absolute error(MAE),probability of detection(POD),false alarm rate,and equitable threat score.Furthermore,the capability of ERA5 to depict heavy rain and drought events was investigated.The results demonstrate that there are spatial and temporal differences in the ability of ERA5 precipitation data to identify daily precipitation events.Among the eight climatic zones,the north temperate zone has the highest accuracy.The r,RMSE,and MAE of ERA5 daily precipitation and station observation are 0.587,4.040 mm·d^(−1),and 1.472 mm·d^(−1),respectively,in the north temperate zone.Precipitation data from the ERA5 are less accurate in the summer and autumn than in the winter and spring.The accuracy of ERA5 precipitation data in areas with elevations greater than>500 m is lower than in areas with elevations of less than≤500 m.When the ERA5 data is used to identify the heavy r
作者
刘婷婷
朱秀芳
郭锐
徐昆
张世喆
LIU Tingting;ZHU Xiufang;GUO Rui;XU Kun;ZHANG Shizhe(Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education,Beijing Normal University,Beijing 100875,China;Institute of Remote Sensing Science and Engineering,Faculty of Geographic Sciences,Beijing Normal University,Beijing 100875,China;State Key Laboratory of Remote Sensing Science,Beijing Normal University,Beijing 100875,China)
出处
《干旱区地理》
CSCD
北大核心
2022年第1期66-79,共14页
Arid Land Geography
基金
国家重点研发计划(2019YFAO606900)
国家自然科学基金面上基金(42077436)资助。
关键词
ERA5数据
降水
暴雨
干旱
ERA5 data
precipitation
heavy rain
drought
