摘要
ERA5-Land再分析产品作为全球重要的地表要素数据,其在干旱监测中的误差评估对进一步提升干旱预警能力和降低灾害风险具有重要意义。利用1981—2020年国家气象信息中心逐日降水格网数据,结合标准化降水指数(Standardized Precipitation Index,SPI),定量评价欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)的第五代再分析陆地产品(Land component of the Fifth Generation of European Reanalysis,ERA5-Land)降水资料在黄河流域及其子流域干旱监测中的误差特征,探讨ERA5-Land降水产品在不同地区和不同时间尺度下对降水的高(低)估以及对干旱特征的描述能力。结果表明:ERA5-Land降水产品在黄河流域对降水量存在明显高估现象,上游地区降水量高估误差最大,中游次之,而下游相对较低。在不同时间尺度下,ERA5-Land降水产品对干湿状况的反映能力存在明显差异,并随时间尺度的增加,差异也增加。针对黄河流域干旱事件,ERA5-Land降水产品存在明显的干旱频次高估和干旱历时低估。上游地区主要以干旱烈度和严重度高估为主,中下游则存在明显的干旱烈度和严重度低估现象。虽然ERA5-Land降水产品能够有效捕获典型干旱事件的空间分布,但对不同等级干旱面积的描述并不准确。因此,使用ERA5-Land降水产品数据进行干旱监测时,需特别注意其高估或低估现象。
The ERA5-Land reanalysis product is an important global data for surface variables,and its error assessment in drought monitoring is of great significance for further improving drought early warning ability and reducing disaster risk.Based on daily precipi-tation grid data from the National Meteorological Information Center during 1981–2020,combined with the standardized precipitation index(SPI),the error characteristics of the Land component of the Fifth Generation of European Reanalysis(ERA5-Land)precipitation data from the European Centre for Medium-Range Weather Forecasts(ECMWF)in monitoring drought in the Yellow River Basin and its sub-basins were evaluated quantitatively,and overestimate or underestimate of precipitation and the ability of describing drought characteristics of ERA5-Land precipitation products in different regions on different time scales were explored.The results show that the ERA5-Land precipitation products are obviously overestimated in the Yellow River Basin,especially in the upper reaches,followed by the middle reaches,and in the lower reaches errors are relatively small.At different time scales,the ability of ERA5-Land precipita-tion products to reflect dry and wet conditions is obviously different,and the difference increases with the increase of time scale.For drought events in the Yellow River Basin,the ERA5-Land precipitation products have obvious overestimation of drought frequency and underestimation of drought duration.In the upper reaches,drought intensity and severity are mainly overestimated,while in the middle and lower reaches,drought intensity and severity are obviously underestimated.Although the ERA5-Land precipitation products can ef-fectively capture the spatial distribution of typical drought events,the description of drought areas of different grades is not accurate.Therefore,when using ERA5-Land precipitation products for drought monitoring,it is necessary to pay special attention to its overesti-mation or underestimation.
作者
朱丽
吕潇雨
郭浩
孟翔晨
田芸菲
ZHU Li;LYU Xiaoyu;GUO Hao;MENG Xiangchen;TIAN Yunfei(Qufu Normal University,Rizhao 276800,Shandong,China)
出处
《干旱气象》
2023年第5期677-687,共11页
Journal of Arid Meteorology
基金
山东省高校优秀青年创新团队项目(2022KJ178)
国家自然科学基金项目(42001363)
山东省自然科学基金青年项目(ZR2021QD055)共同资助。
关键词
ERA5-Land
降水产品
黄河流域
干旱监测
应用评价
ERA5-Land
precipitation product
the Yellow River Basin
drought monitoring
applicability evaluation
