汾渭平原至黄土高原不同海拔高度地区近地面臭氧浓度差异  

Analysis on the difference of near-surface ozone concentration between the Fenwei Plain and the Loess Plateau at different altitudes

作　　者：钱朋 朱彬[1,2] 刘慧敏 蒋伊蓉 张建康 高美美 康磊 QIAN peng;ZHU Bin;LIU Hui-min;JIANG Yi-rong;ZHANG Jian-kang;GAO Mei-mei;KANG lei(Key Open Laboratory of Aerosol and Cloud Precipitation,China Meteorological Administration,Collaborative Innovation Center for Meteorological Disaster Prediction,Early Warning and Evaluation,Nanjing University of Information Science&Technology,Nanjing 210044,China;Key Laboratory of Eco-Environmental and Meteorology for the Qinling Mountains and Loess Plateau,Shaanxi Meteorological Bureau,Xi'an 710016,China;Yulin Meteorological Bureau,Yulin 719000,China)

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心,中国气象局气溶胶与云降水重点开放实验室,江苏南京210044 [2]陕西省气象局秦岭与黄土高原生态环境气象重点实验室,陕西西安710016 [3]榆林市气象局,陕西榆林719000

出　　处：《中国环境科学》2023年第1期77-87,共11页China Environmental Science

基　　金：国家自然科学基金资助项目(92044302);陕西省气象局秦岭和黄土高原生态环境气象重点实验室2020年面上项目(2020G-5);榆林市科技局2020年技术研发项目(YF-2020-030)。

摘　　要：利用2017~2019年中国生态环境监测总站逐小时地面臭氧(O_(3))和二氧化氮(NO_(2))数据,结合再分析气象数据集,分析了从汾渭平原至黄土高原三个不同海拔高度的典型城市郊区(西安:500m、榆林:1100m和鄂尔多斯:1300m)O_(3)浓度的季-月-日变化特征,以及导致三地O_(3)浓度差异可能的化学和气象成因.结果表明:与其他季节比较,夏季三地的O_(3)浓度都较高且差值较小,其中西安昼间O_(3)的净增量最大、夜间净减量也最大且前体物NO_(2)浓度最高,说明西安夏季白天O_(3)光化学反应最强烈、夜间NO滴定O_(3)效应也最强,榆林其次、鄂尔多斯最弱;冬季三地的O_(3)浓度都较低且差异较大,其中西安最低、鄂尔多斯最高,可能是由于冬季白天光化学反应都弱、夜间NO滴定O_(3)效应差异和高海拔地区背景O_(3)浓度高共同导致的,反映了三地O_(3)浓度水平差异不仅受不同NOx水平下局地化学作用影响,还由区域背景值决定.分析还发现,高海拔的鄂尔多斯和榆林二地O_(3)浓度在上午升高的速率快于西安,与二地边界层向上发展的速率一致,可能是由于此时的夹卷效应将高海拔自由对流层的高背景O_(3)向下湍流输送所致.在每个季节雨天夜间,三地的O_(3)浓度均高于其阴、晴天,但是这一差异在西安较弱,而在榆林和鄂尔多斯较强,这进一步意指高海拔地区近地面O_(3)在雨天夜间更强烈地受到高浓度背景O_(3)的影响,一方面是通过降水的拖曳作用,另一方面是因为雨天夜间NO的滴定作用减弱.本研究通过长期观测资料分析,推测了不同海拔高度对近地面O_(3)的影响机制,还需在更多地区进行分析和利用模式开展验证.Using the hourly dataset of ground-level ozone(O_(3))and nitrogen dioxide(NO_(2))collected by the General Ecological and Environmental Monitoring Station of China from 2017 to 2019,combined with reanalysis of meteorological datasets,we analyze the O_(3)concentrations characteristics in seasonal,monthly and diurnal scales in typical suburban areas(Xi’an,500m;Yulin,1100m and Ordos,1300m above sea level)at three different altitudes from the Fenwei Plain to the Loess Plateau.The potential chemical and meteorological causes of the differences in O_(3)concentrations at the three locations are also conducted.The results show that the O_(3)concentrations are high at all three sites with less differences of concentrations in summer.In Xi’an,the net O_(3)increase in daytime,the net decrease in nighttime and the NO_(2)concentrations(one of the precursors of O_(3))are the highest among the three sites in summer,indicating that O_(3)photochemical production in daytime and the NO titration O_(3)effect in nighttime are the strongest in Xi’an,followed by Yulin and Ordos.In winter,O_(3)concentrations in all three sites are low and the lowest in Xi’an and the highest in Erdos,with large differences.This may be due to the combination effect of weak photochemical reactions in daytime,differences in NO titration O_(3)effects at night and background O_(3)concentrations at different altitudes,reflecting that the O_(3)concentration levels at the three sites are not only dominant by local chemistry at different NOx levels,but also determined by regional background values.The study also reveals that O_(3)concentrations in Ordos and Yulin(at the higher altitudes)increase faster in the morning than in Xi’an,consistent with the faster upward increase of the boundary layer height in two sites in the morning,which could be caused by the entrainment effect,downward transport high background O_(3)from free troposphere to the surface by turbulence at this period.During the rainy night in each season,O_(3)concentrations in all three site

关 键 词：O_(3) NO_(2) 海拔高度 光化学反应 夹卷 背景浓度 

分 类 号：X511[环境科学与工程—环境工程]