以复杂地形的天津蓟州为例,通过对比距离蓟州最近的大兴探空站资料与欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)第五代大气再分析(ECMWF Reanalysis v5,ERA5)资料的差异,对基于ERA5资料生成的强对流指数在蓟州的适用性进行检验和评估.结果表明:(1)ERA5资料与大兴探空站探测的位势高度、气温和风速在对流层高度吻合,说明ERA5资料能够描述蓟州高空气象条件,且对低空的表现能力比高空准确,各要素中大气湿度的表现相对较差;(2)基于ERA5生成的对流指数中,与强对流天气密切相关的对流有效位能(convective available potential energy,CAPE)、K 指数、沙瓦特指数(Showalter index,SI)和大气可降水量(precipitable water,PW)与大兴探空站对应参数的相关系数分别达到0.66、0.90、0.93和0.99,表明利用ERA5构建的对流指数能够揭示大气不稳定层结条件;(3)ERA5对流指数变化与蓟州降水过程相对应,ERA5能够反映天气的变化和发展,为强对流潜势分析提供参考.
Validation and application of ERA5 in complex terrain of Jizhou
By comparing the differences between the data of Daxing sounding station,the nearest to Jizhou,Tianjing,and ECMWF(European Centre for Medium-Range Weather Forecasts)Reanalysis v5(ERA5)data,the applicability of the ERA5-derived strong convection index under complex terrain conditions of Jizhou is validated and evaluated.The results are listed below.(1)The geopotential height,air temperature,and wind speed detected by Daxing sounding station are consistent with the corresponding ERA5 in the troposphere,which indicates that ERA5 can represent the meteorological characteristics above Jizhou,and it performs better at low altitude than at high altitude,but has poor performance on atmospheric humidity.(2)The convection indexes based on ERA5,such as CAPE(convective available potential energy),K index,SI(Showalter index),and PW(precipitable water),are all closely related with strong convective weather,and the correlation coefficients between them and the corresponding parameters of Daxing sounding station are 0.66,0.90,0.93,and 0.99,respectively,indicating that these indexes can reveal the stratification instability conditions.(3)The variation of the convection indexes constructed by ERA5 corresponds with the precipitation process in Jizhou,and ERA5 can reflect the change of weather and provide reference for analyzing strong convective potential.
JizhouDaxing sounding stationECMWF Reanalysis v5(ERA5)aerial explorationstrong convective index
万方数据
维普
