气候变化领域集成服务门户(CCPortal): Measurement report: Fast photochemical production of peroxyacetyl nitrate (PAN) over the rural North China Plain during haze events in autumn

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DOI	10.5194/acp-21-17995-2021
	Measurement report: Fast photochemical production of peroxyacetyl nitrate (PAN) over the rural North China Plain during haze events in autumn
	Qiu Y.; Ma Z.; Li K.; Huang M.; Sheng J.; Tian P.; Zhu J.; Pu W.; Tang Y.; Han T.; Zhou H.; Liao H.
发表日期	2021
ISSN	1680-7316
起始页码	17995
结束页码	18010
卷号	21 期号:23
英文摘要	Photochemical pollution over the North China Plain (NCP) is attracting much concern. We usually view peroxyacetyl nitrate (PAN) as the second most important photochemical pollutant featuring high mixing ratios during warm seasons. Our observations at a background site in the NCP identified high PAN concentrations, even during haze events in autumn. The substantial increasing ratios of PAN, by 244 % and 178 %, over the morning hours (08:00-12:00 local time) on 20 and 25 October 2020 were 10.6 and 7.7 times larger than those on clean days. Polluted days are characterized by higher temperature, higher humidity, and anomalous southerly winds compared with clean days. Enhanced local photochemistry has been identified as being the dominant factor that controls the PAN increase in the morning at the rural site, as the time when prevailing wind turns to a southerly wind is too late to promote direct transport of PAN from the polluted urban region. By removing the effect of direct transport of PAN, we provide a quantitative assessment of net PAN chemical production rate of 0.45 ppb h-1 for the mornings of polluted days, also demonstrating the strong local photochemistry. Using observations and calculated photolysis rates, we find that acetaldehyde oxidation by hydroxyl radical (OH) is the primary pathway of peroxyacetyl radical formation at the rural site. Acetaldehyde concentrations and production rates of HOx (HOxCombining double low line OH + HO2) on polluted days are 2.8 and 2 times as large as those on clean days, leading to a remarkable increase in PAN in the morning. Formaldehyde (HCHO) photolysis dominates the daytime HOx production, thus contributing to fast photochemistry of PAN. Our observational results suggest the cause of a rapid increase in PAN during haze events in autumn at a rural site of the NCP and provide evidence of important role of HCHO photolysis in secondary pollutants at lower nitrogen oxide emissions. This highlights the urgency of carrying out strict volatile organic compound controls over the NCP during the cold season and not just in summer. © 2021 Yulu Qiu et al.
语种	英语
scopus关键词	acetaldehyde; autumn; concentration (composition); formaldehyde; haze; high temperature; humidity; hydroxyl radical; peroxyacetyl nitrate; photochemistry; quantitative analysis; China; North China Plain
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246378
作者单位	Institute of Urban Meteorology, China Meteorological Administration, Beijing, 100089, China; Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, China; Beijing Shangdianzi Regional Atmosphere Watch Station, Beijing, 101507, China; Environmental Meteorology Forecast Center of Beijing-Tianjin-Hebei, Beijing, 100089, China; Beijing Weather Modification Office, Beijing, 100089, China; Tianjin Environmental Meteorology Center, Tianjin, 300074, China
推荐引用方式 GB/T 7714	Qiu Y.,Ma Z.,Li K.,et al. Measurement report: Fast photochemical production of peroxyacetyl nitrate (PAN) over the rural North China Plain during haze events in autumn[J],2021,21(23).
APA	Qiu Y..,Ma Z..,Li K..,Huang M..,Sheng J..,...&Liao H..(2021).Measurement report: Fast photochemical production of peroxyacetyl nitrate (PAN) over the rural North China Plain during haze events in autumn.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(23).
MLA	Qiu Y.,et al."Measurement report: Fast photochemical production of peroxyacetyl nitrate (PAN) over the rural North China Plain during haze events in autumn".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.23(2021).