2013~2020年天津市PM_(2.5)-O_(3)污染变化趋势和影响因素分析  

Analysis of Change Trend and Influencing Factors of PM_(2.5)-O_(3)Pollution in Tianjin from 2013 to 2020

作　　者：肖致美 李亚菲 高璟赟 李鹏 蔡子颖 郑乃源 张裕芬[2] 戢运峰 XIAO Zhi-mei;LI Ya-fei;GAO Jing-yun;LI Peng;CAI Zi-ying;ZHENG Nai-yuan;ZHANG Yu-fen;JI Yun-feng(Tianjin Eco-Environmental Monitoring Center,Tianjin 300191,China;State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control,College of Environmental Science and Engineering,Nankai University,Tianjin 300071,China;Tianjin Environmental Meteorological Center,Tianjin 300074,China)

机构地区：[1]天津市生态环境监测中心,天津300191 [2]南开大学环境科学与工程学院,国家环境保护城市空气颗粒物污染防治重点实验室,天津300071 [3]天津市环境气象中心,天津300074

出　　处：《环境科学》2023年第8期4211-4219,共9页Environmental Science

基　　金：国家自然科学基金项目(42177465);天津市科技计划项目(21YFSNSN00200)。

摘　　要：基于2013~2020年高时空分辨率的PM_(2.5)和O_(3)在线监测数据以及气象观测数据,利用KZ(Kolmogorov-Zurbenko)滤波耦合逐步回归等技术,对天津市PM_(2.5)和O_(3)浓度变化趋势、相互关系和影响因素进行了分析.结果表明,与2013年相比,2020年天津市PM_(2.5)浓度下降50.0%,O_(3)浓度上升25.8%.从月际变化来看,与2013~2017年相比,2018~2020年天津市PM_(2.5)浓度月际间差异逐渐缩小,O_(3)浓度从4月开始出现明显上升,污染发生时间节点提前.O_(3)与PM_(2.5)的相关性呈现明显的季节性分布特征,冬季整体呈负相关,夏季正相关且相关性比其他季节高.不同季节O_(3)与PM_(2.5)之间的拟合斜率与相关性系数整体呈正比例关系,拟合斜率与相关性系数的比值逐年升高说明PM_(2.5)对O_(3)生成的抑制作用逐年降低.2013~2020年,天津市PM_(2.5)浓度时间序列的长期分量呈显著下降趋势,其中污染源减排起主导作用,气象因素对PM_(2.5)长期分量的贡献在-3~6μg·m^(-3).PM_(2.5)/CO与NO_(2)/SO_(2)之间关系由2013~2017年间的负相关转变为2018~2020年正相关,说明受减排的影响,NO_(x)对PM_(2.5)中二次组分形成的贡献潜势逐渐增加,PM_(2.5)中主要二次组分由硫酸盐逐渐转向硝酸盐.2013~2020年天津市O_(3)浓度时间序列的长期分量整体表现为上升趋势,前体物排放对O_(3)长期分量的贡献在2013~2018年上升,2019年后开始降低;气象因素对O_(3)长期分量的贡献呈现明显的阶段性变化特点,2013~2016年下降,2016~2020年上升.与2013~2015年相比,2016~2020年夏季典型时段(11:00~16:00)O_(3)-NO_(2)间的拟合曲线向NO_(2)低值方向偏移,反映出该时段NO_(x)的减排取得一定效果,2019~2020年的拟合曲线整体下移,说明近两年NO_(x)和VOCs减排效果较明显,对降低O_(3)有重要作用.The change trend,relationship,and influencing factors of PM_(2.5)and O_(3)concentrations were analyzed by using a Kolmogorov-Zurbenko(KZ)filter coupled with stepwise multiple linear regression analysis and the spatiotemporal resolution monitoring data of PM_(2.5)and O_(3)and meteorological data observed in Tianjin from 2013 to 2020.The results showed that a significant decreasing trend of PM_(2.5)concentrations by 50.0%was observed from 2013 to 2020,whereas an increasing trend for O_(3)concentrations by 25.8%was observed from 2013 to 2020.Compared with that in 2013 to 2017,the monthly difference in PM_(2.5)concentrations gradually narrowed from 2018 to 2020,whereas the concentration of O_(3)had increased significantly since April,and the occurrence time of O_(3)pollution was advanced.The correlation coefficient patterns of O_(3)and PM_(2.5)showed obvious seasonal distribution characteristics.The correlation coefficients were negatively correlated in winter and positively correlated in the summer,and the correlation coefficients in summer were generally higher than those in other seasons.The correlation coefficients between O_(3)and PM_(2.5)in different seasons were positively proportional to the fitting slope.The ratios of the fitting slope to correlation coefficients showed an increasing trend,which might reflect that the inhibitory effect of PM_(2.5)on O_(3)formation in the PM_(2.5)-O_(3)interaction mechanism might have been weakened due to the impact of emission reduction.A significant decreasing trend was observed for the longterm trend components of the PM_(2.5)concentration time series;emission reduction played a leading role,and meteorological factors contributed-3 to 6μg·m^(-3).The changes in the relationship between the PM_(2.5)/CO ratio versus NO_(2)/SO_(2)from negative to positive were observed from 2013-2017 to 2018-2020 in Tianjin,which could indicate the enhanced contribution potential of nitrogen oxides to the main secondary component formation of PM_(2.5)under the current emission reduction scen

关 键 词：天津 PM_(2.5) 臭氧(O_(3)) 变化趋势 影响因素 

分 类 号：X51[环境科学与工程—环境工程]