| 2013~2020年天津市PM2.5-O3污染变化趋势和影响因素分析 |
| 摘要点击 3086 全文点击 657 投稿时间：2022-10-20 修订日期：2022-11-01 |
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| 中文关键词 天津 PM2.5 臭氧(O3) 变化趋势 影响因素 |
| 英文关键词 Tianjin PM2.5 ozone (O3) change trend influencing factors |
| 作者 | 单位 | E-mail | | 肖致美 | 天津市生态环境监测中心, 天津 300191 | xiaozhimei01@163.com | | 李亚菲 | 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 | | | 高璟赟 | 天津市生态环境监测中心, 天津 300191 | | | 李鹏 | 天津市生态环境监测中心, 天津 300191 | | | 蔡子颖 | 天津市环境气象中心, 天津 300074 | | | 郑乃源 | 天津市生态环境监测中心, 天津 300191 | | | 张裕芬 | 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 | zhafox@nankai.edu.cn | | 戢运峰 | 天津市生态环境监测中心, 天津 300191 | yf_2100@163.com |
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| 中文摘要 |
| 基于2013~2020年高时空分辨率的PM2.5和O3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PM2.5和O3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PM2.5浓度下降50.0%,O3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PM2.5浓度月际间差异逐渐缩小,O3浓度从4月开始出现明显上升,污染发生时间节点提前.O3与PM2.5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O3与PM2.5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PM2.5对O3生成的抑制作用逐年降低.2013~2020年,天津市PM2.5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PM2.5长期分量的贡献在-3~6μg ·m-3.PM2.5/CO与NO2/SO2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,NOx对PM2.5中二次组分形成的贡献潜势逐渐增加,PM2.5中主要二次组分由硫酸盐逐渐转向硝酸盐.2013~2020年天津市O3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O3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O3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)O3-NO2间的拟合曲线向NO2低值方向偏移,反映出该时段NOx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NOx和VOCs减排效果较明显,对降低O3有重要作用. |
| 英文摘要 |
| The change trend, relationship, and influencing factors of PM2.5 and O3 concentrations were analyzed by using a Kolmogorov-Zurbenko (KZ) filter coupled with stepwise multiple linear regression analysis and the spatiotemporal resolution monitoring data of PM2.5 and O3 and meteorological data observed in Tianjin from 2013 to 2020. The results showed that a significant decreasing trend of PM2.5 concentrations by 50.0% was observed from 2013 to 2020, whereas an increasing trend for O3 concentrations by 25.8% was observed from 2013 to 2020. Compared with that in 2013 to 2017, the monthly difference in PM2.5 concentrations gradually narrowed from 2018 to 2020, whereas the concentration of O3 had increased significantly since April, and the occurrence time of O3 pollution was advanced. The correlation coefficient patterns of O3 and PM2.5 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 O3 and PM2.5 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 PM2.5 on O3 formation in the PM2.5-O3 interaction mechanism might have been weakened due to the impact of emission reduction. A significant decreasing trend was observed for the long-term trend components of the PM2.5 concentration time series; emission reduction played a leading role, and meteorological factors contributed -3 to 6 μg·m-3. The changes in the relationship between the PM2.5/CO ratio versus NO2/SO2 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 PM2.5 under the current emission reduction scenarios, and the main secondary components of PM2.5in Tianjin gradually changed from sulfate to nitrate. An overall upward trend was observed for the long-term trend components of the O3 concentration time series from 2013 to 2020, and the contribution of precursor emissions to the long-term component of O3 increased from 2013 to 2018 and began to decrease after 2019. The contribution of meteorological factors to the long-term component of O3 presented an obvious stage change, showing a downward trend from 2013 to 2016 and an upward trend from 2016 to 2020. The O3 concentration presented a non-linear relationship with NO2 during the period of intense atmospheric photochemical processes (11:00-16:00) in summer. Compared with that in 2013-2015, the fitting curve of O3 and NO2 showed an obvious offset to the low value of NO2 from 2016 to 2020, which reflected that the NOx emission reduction in this period achieved certain results. Compared with that in 2018, the fitting curve of O3 and NO2 moved downward from 2019 to 2020, which may reflect that NOx and VOCs emission reduction had a non-negligible effect on the O3 decline at this stage. |
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