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DOI	10.5194/acp-22-7005-2022
	OH and HO2 radical chemistry at a suburban site during the EXPLORE-YRD campaign in 2018
	Ma, Xuefei; Tan, Zhaofeng; Lu, Keding; Yang, Xinping; Chen, Xiaorui; Wang, Haichao; Chen, Shiyi; Fang, Xin; Li, Shule; Li, Xin; Liu, Jingwei; Liu, Ying; Lou, Shengrong; Qiu, Wanyi; Wang, Hongli; Zeng, Limin; Zhang, Yuanhang
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	7005
结束页码	7028
卷号	22 期号:10 页码:24
英文摘要	The first OH and HO(2 )radical observation in Yangtze River Delta, one of the four major urban agglomerations in China, was carried out at a suburban site (Taizhou) in summer 2018 from May to June, aiming to elucidate the atmospheric oxidation capacity in this region. The maximum diurnal averaged OH and HO2 concentrations were 1.0x10(7) and 1.1x10(9) cm(-3), respectively, which were the second highest HOx (sum of OH and HO2) radical concentrations observed in China. HONO photolysis was the dominant radical primary source, accounting for 42 % of the total radical initiation rate. Other contributions were from carbonyl photolysis (including HCHO, 24 %), O-3 photolysis (17 %), alkene ozonolysis (14 %), and NO3 oxidation (3 %). A chemical box model based on the RACM2-LIM1 mechanism could generally reproduce the observed HOx radicals, but systematic discrepancy remained in the afternoon for the OH radical, when the NO mixing ratio was less than 0.3 ppb. An additional recycling mechanism equivalent to 100 ppt NO was capable to fill the gap. The sum of monoterpenes was on average up to 0.4 ppb during daytime, which was all allocated to alpha-pinene in the base model. A sensitivity test without monoterpene input showed the modeled OH and HO2 concentrations would increase by 7 % and 4 %, respectively, but modeled RO2 concentration would significantly decrease by 23 %, indicating that monoterpene was an important precursor of RO2 radicals in this study. Consequently, the daily integrated net ozone production would reduce by 6.3 ppb without monoterpene input, proving the significant role of monoterpene in the photochemical O-3 production in this study. In addition, the generally good agreement between observed and modeled HOx concentrations suggested no significant HO2 heterogeneous uptake process during this campaign. Incorporation of HO2 heterogeneous uptake process would worsen the agreement between HOx radical observation and simulation, and the discrepancy would be beyond the combined measurement-model uncertainties using an effective uptake coefficient of 0.2. Finally, the ozone production efficiency (OPE) was only 1.7 in this study, a few folds lower than other studies in (sub)urban environments. The low OPE indicated a slow radical propagation rate and short chain length. As a consequence, ozone formation was suppressed by the low NO concentration in this study.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000803029700001
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/273739
作者单位	Peking University; Helmholtz Association; Research Center Julich; Sun Yat Sen University; Peking University; Chinese Academy of Sciences
推荐引用方式 GB/T 7714	Ma, Xuefei,Tan, Zhaofeng,Lu, Keding,et al. OH and HO2 radical chemistry at a suburban site during the EXPLORE-YRD campaign in 2018[J],2022,22(10):24.
APA	Ma, Xuefei.,Tan, Zhaofeng.,Lu, Keding.,Yang, Xinping.,Chen, Xiaorui.,...&Zhang, Yuanhang.(2022).OH and HO2 radical chemistry at a suburban site during the EXPLORE-YRD campaign in 2018.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(10),24.
MLA	Ma, Xuefei,et al."OH and HO2 radical chemistry at a suburban site during the EXPLORE-YRD campaign in 2018".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.10(2022):24.