Mengxue Tong, Yanli Zhang, Shaoxuan Xiao, Chenglei Pei, Jun Wang, Runqi Zhang, Xiaoqing Huang, Wei Song, Xinming Wang
{"title":"Role of Organic Vapor Precursors in Secondary Organic Aerosol Formation: Concurrent Observations of IVOCs and VOCs in Guangzhou","authors":"Mengxue Tong, Yanli Zhang, Shaoxuan Xiao, Chenglei Pei, Jun Wang, Runqi Zhang, Xiaoqing Huang, Wei Song, Xinming Wang","doi":"10.1029/2024JD041018","DOIUrl":null,"url":null,"abstract":"<p>Secondary organic aerosol (SOA) formed through the atmospheric transformation of organic vapors constitutes a significant portion of fine particulate matter or PM<sub>2.5</sub>. While recent laboratory studies underscore the importance of intermediate-volatility organic compounds (IVOCs) as key precursors to SOA, field observations that recognize the role of both volatile organic compounds (VOCs) and IVOCs in SOA formation remain scarce. In this study, we conducted concurrent measurements of VOCs and IVOCs in ambient air at urban and suburban sites in Guangzhou during a PM<sub>2.5</sub> pollution event in winter 2021. The results reveal that between 12:00–15:00 local time, the photochemically adjusted initial concentrations of VOCs at both sites were approximately 7 times higher than that of IVOCs. However, the SOA formation potential (SOAFP) of primary hydrocarbon IVOCs exceeded that of VOCs by over 3–4 times. Receptor modeling results further indicated that while ship emissions contributed to less than 10% of the C2–C22 primary hydrocarbons concentration (VOCs + primary carbonaceous IVOCs), they accounted for the most significant source (approximately 40%) of SOA formation. This study highlights the substantial role of IVOCs in SOA formation and emphasizes the importance of future PM<sub>2.5</sub> pollution control measures targeting major IVOCs contributors, such as ship emissions in harbor cities.</p>","PeriodicalId":15986,"journal":{"name":"Journal of Geophysical Research: Atmospheres","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research: Atmospheres","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2024JD041018","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Secondary organic aerosol (SOA) formed through the atmospheric transformation of organic vapors constitutes a significant portion of fine particulate matter or PM2.5. While recent laboratory studies underscore the importance of intermediate-volatility organic compounds (IVOCs) as key precursors to SOA, field observations that recognize the role of both volatile organic compounds (VOCs) and IVOCs in SOA formation remain scarce. In this study, we conducted concurrent measurements of VOCs and IVOCs in ambient air at urban and suburban sites in Guangzhou during a PM2.5 pollution event in winter 2021. The results reveal that between 12:00–15:00 local time, the photochemically adjusted initial concentrations of VOCs at both sites were approximately 7 times higher than that of IVOCs. However, the SOA formation potential (SOAFP) of primary hydrocarbon IVOCs exceeded that of VOCs by over 3–4 times. Receptor modeling results further indicated that while ship emissions contributed to less than 10% of the C2–C22 primary hydrocarbons concentration (VOCs + primary carbonaceous IVOCs), they accounted for the most significant source (approximately 40%) of SOA formation. This study highlights the substantial role of IVOCs in SOA formation and emphasizes the importance of future PM2.5 pollution control measures targeting major IVOCs contributors, such as ship emissions in harbor cities.
期刊介绍:
JGR: Atmospheres publishes articles that advance and improve understanding of atmospheric properties and processes, including the interaction of the atmosphere with other components of the Earth system.