ERA5再分析云量在大气环境评估中的适用性研究  

Research on Applicability of ERA5 Reanalysis Cloud Cover in Assessment of Atmospheric Environment

作　　者：许启慧[1] 张金龙 许康 井元元 XU Qihui;ZHANG Jinlong;XU Kang;JING Yuanyuan(Hebei Climate Centre,Shijiazhuang 050021;Hebei Meteorological Information Centre,Shijiazhuang 050021)

机构地区：[1]河北省气候中心,石家庄050021 [2]河北省气象信息中心,石家庄050021

出　　处：《气象科技》2023年第2期183-191,共9页Meteorological Science and Technology

基　　金：河北省气象局科研开发项目(19kyd01);河北省地方十三五生态环境气象保障工程项目(201810979)共同资助。

摘　　要：以河北省7个国家级气象站为例,利用1979—2013年ERA5云量和地面实测云量数据,依国标推荐法计算混合层高度,通过公式推导出通风量和大气自净能力指数,比较两套数据的计算结果,对ERA5再分析云量在大气环境评估中的适用性进行了研究;采用ERA5云量计算2013年3月至2021年2月的大气自净能力指数,对其与PM2.5浓度之间的关系进行分析。结果表明:(1)两种云量资料计算的月平均混合层高度、通风量和大气自净能力指数的相对误差近似符合正态分布,主要集中在0~5%;各月混合层高度:相对误差>通风量>大气自净能力指数,相关性则相反。秋冬季的相对误差(相关系数)大都低(高)于春夏季,邢台、石家庄和保定的误差明显小于其他站。(2)利用两种云量数据计算的大气自净能力指数的多年平均相对误差最小,通风量的次之,历年值的相关性和偏差也是中南部站点的更为理想。(3)2013年3月至2021年2月,各站月平均大气自净能力指数和PM2.5浓度呈反向相关,中南部站点的相关性更为显著。Taking seven national weather stations in Hebei Province as an example,the mixed layer height,ventilation capacity and atmospheric self-cleaning ability index are calculated using ERA5 cloud data and measured cloud data from 1979 to 2013,and a preliminarily assessment of ERA5 reanalysis cloud data is conducted through comparing the results by two sets of data calculated.ERA5 cloud cover is used to calculate the atmospheric self-cleaning capacity index from March 2013 to February 2021,and the relationship between it and PM2.5 concentration is analyzed.The results are as follows:(1)The monthly average relative errors between the mixed layer height,ventilation capacity,and atmospheric self-cleaning ability index calculated by using two sets of cloud data approximately accord with the normal distribution,the highest frequency occurring in 0-5%;the monthly relative error of the mixed layer height>ventilation capacity>atmospheric self-cleaning ability index;and the correlation is opposite.The relative errors(correlation coefficients)of autumn and winter are mostly lower(higher)in spring and summer.The monthly mean relative errors of Xingtai,Shijiazhuang and Baoding are significantly smaller than those of other stations.(2)The annual average relative error of the atmospheric self-cleaning ability index is the smallest,followed by ventilation capacity.The fitting degree and deviation of the annual values in the south-central stations are also more ideal.(3)From March 2013 to February 2021,the monthly average atmospheric self-cleaning ability index and PM2.5 concentration are inversely correlated at all stations.The correlativeness is more obvious in the central and southern stations.

关 键 词：云量 ERA5 相对误差 大气自净能力指数 

分 类 号：X16[环境科学与工程—环境科学] P49[天文地球—大气科学及气象学]