我国城市大气PM_(2.5)与O_(3)浓度相关性的时空特征分析  

The temporal and spatial distribution of the correlation between PM_(2.5) and O_(3) contractions in the urban atmosphere of China

作　　者：裘彦挺 吴志军[1] 尚冬杰 张子睿 徐楠 宗韬谋 赵罡 汤丽姿 郭松 王帅[2] 刀谞[2] 王晓斐[2] 唐桂刚[2] 胡敏[1] Yanting Qiu;Zhijun Wu;Dongjie Shang;Zirui Zhang;Nan Xu;Taomou Zong;Gang Zhao;Lizi Tang;Song Guo;Shuai Wang;Xu Dao;Xiaofei Wang;Guigang Tang;Min Hu(International Joint Laboratory for Regional Pollution Control,Ministry of Education,State Key Joint Laboratory of Environmental Simulation and Pollution Control,College of Environmental Science and Engineering,Peking University,Beijing 100871,China;China National Environmental Monitoring Centre,Beijing 100012,China)

机构地区：[1]北京大学环境科学与工程学院,环境模拟与污染控制国家重点联合实验室,教育部区域污染控制国际合作联合实验室,北京100871 [2]中国环境监测总站,北京100012

出　　处：《科学通报》2022年第18期2008-2017,共10页Chinese Science Bulletin

基　　金：O_(3)和PM_(2.5)复合污染协同防控科技攻关预研课题(8201701819);江苏省PM_(2.5)与臭氧协同控制重大专项(2019023)资助。

摘　　要：近些年,我国大气PM_(2.5)的质量浓度显著降低,O_(3)污染加剧.为了厘清PM_(2.5)和O_(3)浓度相关性的时空差异,本研究分析了我国城市大气PM_(2.5)浓度与O_(3)日最大8 h滑动平均值(MDA8 O_(3))和大气总氧化剂(O_(x)=O_(3)+NO_(2))浓度之间的相关性.2015年以来,PM_(2.5)与O_(3)双超标天数大幅下降,现阶段双超标情况主要发生在京津冀地区的4~5月.在40°N以南的地区,PM_(2.5)与O_(3)浓度的相关性呈现显著的“南高北低、夏高冬低”的时空分布规律.较强的正相关关系出现在中纬度京津冀地区的夏季以及低纬度的珠江三角洲地区,表明这些区域O_(3)和PM_(2.5)的浓度具有相同的变化趋势;而在京津冀地区的冬季,由于PM_(2.5)中一次组分占比增高以及较弱的O_(3)光化学生成,O_(3)和PM_(2.5)浓度具有相反的变化趋势.不同于PM_(2.5)与MDA8 O_(3)之间的关系,PM_(2.5)与O_(x)在不同季节均表现出较好的正相关性,表明我国大气的强氧化性驱动了PM_(2.5)中二次组分的生成.在O_(3)超标的情况下(MDA8 O_(3)>160μg/m^(3)),PM_(2.5)和O_(3)浓度的相关性与PM_(2.5)浓度有关,当PM_(2.5)浓度低于50μg/m^(3)时,O_(3)与PM_(2.5)浓度具有较好的正相关性,呈现同步变化趋势;当PM_(2.5)浓度进一步增加时,二者浓度具有相反的变化趋势,说明更高浓度的PM_(2.5)可能会抑制O_(3)生成.The mass concentrations of fine particles(PM_(2.5))have decreased significantly in China in recent years,while surface ozone pollution shows an opposite trend.To better understand the combined PM_(2.5) and O_(3) pollution in China’s urban atmosphere,the Spearman correlation between PM_(2.5) mass concentration and daily maximum 8-hour average ozone concentration(MDA8 O_(3))was analyzed in this study,as well as the correlation between the concentrations of PM_(2.5) and O_(x)(O_(x)=O_(3)+NO_(2)).Since 2015,the number of days when both O_(3) and PM_(2.5) concentrations exceed the national ambient air quality standards has decreased significantly with the decrease in PM_(2.5) concentrations.The pollution combined O_(3) and PM_(2.5) usually occurs in April and May in the Beijing-Tianjin-Hebei(BTH)area.It is worth noting that the correlations between PM_(2.5) and MDA8 O_(3) concentrations depend on regions and seasons on south of 40°N in China.A stronger positive correlation between the concentrations of PM_(2.5) and MDA8 O_(3) in the Pearl River Delta(PRD)area was obtained throughout the year(R>0.6).In the BTH area,this type of relationship occurs only in summer(R~0.5)whereas in winter,a weak negative correlation between PM_(2.5) and MDA8 O_(3) concentrations was observed(R<–0.2).This may be due to a higher primary contribution of PM_(2.5) and a low concentration of O_(3) due to low photochemical production compared to summer in wintertime.For the case of O_(3) concentration exceeds national ambient air quality standards in Beijing and Xuzhou,MDA8 O_(3) and PM_(2.5) concentrations correlate positively when PM_(2.5)≤50μg/m^(3).In contrast,when PM_(2.5)>50μg/m^(3),a weak negative correlation was observed(R~–0.1),suggesting that high concentrations of particulate matter may inhibit O_(3) formation on days when is polluted.However,the mechanism of such phenomenon remains confusing due to the complex relationship between the production of O_(3) and PM_(2.5).Meanwhile,PM_(2.5) and MDA8 O_(3) concentrations show a

关 键 词：细颗粒物 臭氧 大气污染 相关性分析 

分 类 号：X51[环境科学与工程—环境工程]