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DOI	10.5194/acp-20-14847-2020
	Elevated levels of OH observed in haze events during wintertime in central Beijing
	Slater E.J.; Whalley L.K.; Woodward-Massey R.; Ye C.; Lee J.D.; Squires F.; Hopkins J.R.; Dunmore R.E.; Shaw M.; Hamilton J.F.; Lewis A.R.; Crilley L.R.; Kramer L.; Bloss W.; Vu T.; Sun Y.; Xu W.; Yue S.; Ren L.; Joe F. Acton W.; Nicholas Hewitt C.; Wang X.; Fu P.; Heard D.E.
发表日期	2020
ISSN	1680-7316
起始页码	14847
结束页码	14871
卷号	20 期号:23
英文摘要	Wintertime in situ measurements of OH, HO2 and RO2 radicals and OH reactivity were made in central Beijing during November and December 2016. Exceptionally elevated NO was observed on occasions, up to 250 ppbv. The daily maximum mixing ratios for radical species varied significantly day-To-day over the ranges 1 8106 cm 3 (OH), 0.2 1:5108 cm 3 (HO2) and 0.3 2:5108 cm 3 (RO2). Averaged over the full observation period, the mean daytime peak in radicals was 2:7106, 0:39108 and 0:88 108 cm 3 for OH, HO2 and total RO2, respectively. The main daytime source of new radicals via initiation processes (primary production) was the photolysis of HONO (83 %), and the dominant termination pathways were the reactions of OH with NO and NO2, particularly under polluted haze conditions. The Master Chemical Mechanism (MCM) v3.3.1 operating within a box model was used to simulate the concentrations of OH, HO2 and RO2. The model underpredicted OH, HO2 and RO2, especially when NO mixing ratios were high (above 6 ppbv). The observation-To-model ratio of OH, HO2 and RO2 increased from 1 (for all radicals) at 3 ppbv of NO to a factor of 3, 20 and 91 for OH, HO2 and RO2, respectively, at 200 ppbv of NO. The significant underprediction of radical concentrations by the MCM suggests a deficiency in the representation of gas-phase chemistry at high NOx . The OH concentrations were surprisingly similar (within 20% during the day) in and outside of haze events, despite j(O1D) decreasing by 50% during haze periods. These observations provide strong evidence that gasphase oxidation by OH can continue to generate secondary pollutants even under high-pollution episodes, despite the reduction in photolysis rates within haze. © 2020 BMJ Publishing Group. All rights reserved.
英文关键词	atmospheric pollution; concentration (composition); haze; hydroxide; hydroxyl radical; mixing ratio; nitrogen oxides; oxidation; photolysis; winter; Beijing [China]; China
语种	英语
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/168924
作者单位	School of Chemistry, University of Leeds, Leeds, LS2 9JT, United Kingdom; National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, United Kingdom; National Centre for Atmospheric Science, University of York, Heslington, York, YO10 5DD, United Kingdom; Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, Heslington, York, YO10 5DD, United Kingdom; School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, 40 Huayanli, Chaoyang District, Beijing, 100029, China; Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YW, United Kingdom; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Wushan, Tianhe District, Guangzhou, GD 510640, China; Institute of Surfa...
推荐引用方式 GB/T 7714	Slater E.J.,Whalley L.K.,Woodward-Massey R.,et al. Elevated levels of OH observed in haze events during wintertime in central Beijing[J],2020,20(23).
APA	Slater E.J..,Whalley L.K..,Woodward-Massey R..,Ye C..,Lee J.D..,...&Heard D.E..(2020).Elevated levels of OH observed in haze events during wintertime in central Beijing.Atmospheric Chemistry and Physics,20(23).
MLA	Slater E.J.,et al."Elevated levels of OH observed in haze events during wintertime in central Beijing".Atmospheric Chemistry and Physics 20.23(2020).