{"title":"Disentangling the effects of meteorology and emissions from anthropogenic and biogenic sources on the increased surface ozone in Eastern China","authors":"","doi":"10.1016/j.atmosres.2024.107699","DOIUrl":null,"url":null,"abstract":"<div><div>China's Clean Air Actions have substantially improved ambient PM<sub>2.5</sub> air quality since 2013. However, ozone (O<sub>3</sub>) pollution in urban areas has worsened in recent years, particularly in the eastern region. The formation of O<sub>3</sub> in these high emission areas is highly complex and regulated by numerous factors. Utilizing the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), this study conducted a comprehensive analysis through nine sensitivity experiments for the years 2013 and 2017, aimed at disentangling the relative contributions of major factors (e.g., meteorological factors, anthropogenic emissions, biogenic emissions, and aerosol feedback mechanisms) to the observed O<sub>3</sub> concentration trends in Jiangsu, a developed region of China with increasing trend of O<sub>3</sub> level. Our findings indicate a pronounced increase in mean daily maximum 8-h average (MDA8) O<sub>3</sub> levels in the economically vibrant southern Jiangsu, contrasted with a decrease in the less developed northern regions. The study identifies anthropogenic emissions change as the primary driver of O<sub>3</sub> variations, with significant impacts also attributed to meteorological conditions and aerosol feedback effects, while biogenic emission shifts play a lesser role. In terms of meteorological factors, we discovered that the alteration in meteorological thermal factors (enhanced solar radiation and temperatures) in 2017, compared to 2013, exerted a more pronounced influence on the formation of O<sub>3</sub> than the change in thermally driven dynamic factors (boundary layer height and wind speed). Moreover, the study observes a shift in O<sub>3</sub> formation sensitivity from VOC-sensitive to transitional or NO<sub>X</sub>-sensitive regimes, signifying a notable transformation in the regional atmospheric chemistry conducive to O<sub>3</sub> generation. Aerosol feedback effects, through complex pathways including photolysis rate alterations and modifications in the vertical O<sub>3</sub> distribution, further compound the challenge of mitigating O<sub>3</sub> levels. Our research underscores the necessity for adaptive, region-specific strategies to mitigate O<sub>3</sub> pollution, providing potential insights for policymakers to formulate effective control measures.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":null,"pages":null},"PeriodicalIF":4.5000,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Atmospheric Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0169809524004812","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
China's Clean Air Actions have substantially improved ambient PM2.5 air quality since 2013. However, ozone (O3) pollution in urban areas has worsened in recent years, particularly in the eastern region. The formation of O3 in these high emission areas is highly complex and regulated by numerous factors. Utilizing the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), this study conducted a comprehensive analysis through nine sensitivity experiments for the years 2013 and 2017, aimed at disentangling the relative contributions of major factors (e.g., meteorological factors, anthropogenic emissions, biogenic emissions, and aerosol feedback mechanisms) to the observed O3 concentration trends in Jiangsu, a developed region of China with increasing trend of O3 level. Our findings indicate a pronounced increase in mean daily maximum 8-h average (MDA8) O3 levels in the economically vibrant southern Jiangsu, contrasted with a decrease in the less developed northern regions. The study identifies anthropogenic emissions change as the primary driver of O3 variations, with significant impacts also attributed to meteorological conditions and aerosol feedback effects, while biogenic emission shifts play a lesser role. In terms of meteorological factors, we discovered that the alteration in meteorological thermal factors (enhanced solar radiation and temperatures) in 2017, compared to 2013, exerted a more pronounced influence on the formation of O3 than the change in thermally driven dynamic factors (boundary layer height and wind speed). Moreover, the study observes a shift in O3 formation sensitivity from VOC-sensitive to transitional or NOX-sensitive regimes, signifying a notable transformation in the regional atmospheric chemistry conducive to O3 generation. Aerosol feedback effects, through complex pathways including photolysis rate alterations and modifications in the vertical O3 distribution, further compound the challenge of mitigating O3 levels. Our research underscores the necessity for adaptive, region-specific strategies to mitigate O3 pollution, providing potential insights for policymakers to formulate effective control measures.
期刊介绍:
The journal publishes scientific papers (research papers, review articles, letters and notes) dealing with the part of the atmosphere where meteorological events occur. Attention is given to all processes extending from the earth surface to the tropopause, but special emphasis continues to be devoted to the physics of clouds, mesoscale meteorology and air pollution, i.e. atmospheric aerosols; microphysical processes; cloud dynamics and thermodynamics; numerical simulation, climatology, climate change and weather modification.