长三角地区近地层臭氧高值特征及其成因分析  

Characteristics and cause analysis of surface high ozone in the Yangtze River Delta

作　　者：牟显金赞 侯雪伟[1,2] 朱小东 MOU Xianjinzan;HOU Xuewei;ZHU Xiaodong(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Key Laboratory of Meteorological Disaster,Ministry of Education,Joint International Research Laboratory of Climate and Environment Change,Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,Nanjing University of Information Science and Technology,Nanjing,210044,China;Key Laboratory of Atmospheric Chemistry,China Meteorological Administration,Beijing,100081,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,气象灾害教育部重点实验室,气候与环境变化国际合作联合实验室,中国气象局气溶胶与云降水重点开放实验室,南京210044 [2]中国气象局大气化学重点开放实验室,北京100081

出　　处：《环境化学》2025年第3期876-889,共14页Environmental Chemistry

基　　金：国家重点研发计划项目(2022YFC3701204);中国气象局大气化学重点开放实验室开放课题(2023B05);安徽省重点研究与开发计划项目(2022h11020008)资助.

摘　　要：为研究长三角地区近地层臭氧污染现状及成因,对2018年3月1日至2021年2月28日三年间环境空气质量数据中的臭氧、二氧化氮和同期欧洲中期天气预报中心全球气候第五代大气再分析数据(ECMWF ERA5)进行了深入分析,结果表明,2018年至2020年间,长三角地区臭氧浓度呈现夏季最高,春季次之,冬季最低的季节变化特征.空间分布上呈现明显的“北高南低”特征,春季和夏季的南北差异较明显,而秋、冬季的臭氧浓度在空间上分布较均匀.臭氧浓度日变化呈单峰型分布,06:00—08:00达到最低值,14:00—16:00达到最高值;臭氧污染事件主要发生在夏季的苏南和皖苏北地区;2018年月平均臭氧浓度呈单峰型分布,6月份达最高,2019年和2020年均呈双峰结构,受疫情影响,2020年的峰值浓度略有降低.2019年5月31日至6月19日期间,徐州地区臭氧污染持续20 d,南京地区持续18 d,为近三年长三角典型城市地区臭氧污染持续最长的时段.臭氧污染期间,两地的臭氧8 h滑动平均日最大浓度一直保持在高位.此外,温度达到峰值的时间较臭氧浓度峰值总是提前1 h左右,这可能与近地面大气光化学对气象条件响应速度的滞后性有关;徐州地区和南京地区发生臭氧污染事件的成因多与局地光化学反应有关,降雨量大幅下降也有一定贡献.除此外,徐州和南京两地在此期间存在两次明显的平流层向对流层传输过程(STT),是臭氧浓度升高的另一原因.此外,徐州和南京受南风和偏南风影响,缓慢的臭氧区域水平输送作用也可能会加剧本地臭氧污染.In order to clarify the current situation and causes of ozone pollution in the Yangtze River Delta region,a comprehensive analysis was conducted based on observed ozone and nitrogen dioxide,and ERA5 reanalysis data from March 1,2018 to February 28,2021.The results reveal that ozone concentrations in the Yangtze River Delta region show seasonal change with the highest concentration in summer,and the lowest in winter from 2018 to 2020.The spatial distribution shows a“high in the north and low in the south”feature,and the north-south differences of ozone concentration are more significant in spring and summer,while it is insignificant in autumn and winter.The daily variation of ozone concentration shows a single peak distribution,reaching the lowest value from 06:00 to 08:00 and the highest value from 14:00 to 16:00(local time);The ozone pollution events mainly occur in southern Jiangsu and northern Anhui during summer;The monthly ozone concentration showed a unimodal distribution in 2018,reaching the highest in June,and a bimodal structure in 2019 and 2020,but due to the impact of COVID restrictions,the peak concentration in 2020 decreased.During the period from May 31 to June 19,2019,ozone pollution lasts for 20 days in Xuzhou,18 days in Nanjing,which is a longest period with ozone pollution in these three years.During the ozone pollution period,the daily maximum concentrations of ozone in the two regions keep in high values.In addition,the peak time of air temperature is always about 1 h earlier than the peak of surface ozone concentration,which may be related to the response lag of atmospheric photochemistry to meteorological conditions.The causes of ozone pollution events in Xuzhou and Nanjing are mostly related to the local photochemical reactions,a significant decrease in rainfall also contributes to the high ozone concentration.In addition,there are two obvious stratosphere-troposphere transport(STT)processes during this period,which also contribute to ozone pollution.The advection transport of ozone in

关 键 词：长江三角洲 臭氧污染 时空特征 平流层—对流层输送. 

分 类 号：X-1[环境科学与工程] O6[理学—化学]