气候变化领域集成服务门户(CCPortal): Radical chemistry in the Pearl River Delta: observations and modeling of OH and HO2 radicals in Shenzhen in 2018

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DOI	10.5194/acp-22-12525-2022
	Radical chemistry in the Pearl River Delta: observations and modeling of OH and HO2 radicals in Shenzhen in 2018
	Yang, Xinping; Lu, Keding; Ma, Xuefei; Gao, Yue; Tan, Zhaofeng; Wang, Haichao; Chen, Xiaorui; Li, Xin; Huang, Xiaofeng; He, Lingyan; Tang, Mengxue; Zhu, Bo; Chen, Shiyi; Dong, Huabin; Zeng, Limin; Zhang, Yuanhang
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	12525
结束页码	12542
卷号	22 期号:18 页码:18
英文摘要	The ambient radical concentrations were measured continuously by laser-induced fluorescence during the STORM (STudy of the Ozone foRmation Mechanism) campaign at the Shenzhen site, located in the Pearl River Delta in China, in the autumn of 2018. The diurnal maxima were 4.5x10(6) cm(-3) for OH radicals and 4.2x10(8) cm(-3) for HO2 radicals (including an estimated interference of 23 %-28 % from RO2 radicals during the daytime), respectively. The state-of-the-art chemical mechanism underestimated the observed OH concentration, similar to the other warm-season campaigns in China. The OH underestimation was attributable to the missing OH sources, which can be explained by the X mechanism. Good agreement between the observed and modeled OH concentrations was achieved when an additional numerical X equivalent to 0.1 ppb NO concentrations was added into the base model. The isomerization mechanism of RO2 derived from isoprene contributed approximately 7 % to the missing OH production rate, and the oxidation of isoprene oxidation products (MACR and MVK) had no significant impact on the missing OH sources, demonstrating further exploration of unknown OH sources is necessary. A significant HO2 heterogeneous uptake was found in this study, with an effective uptake coefficient of 0.3. The model with the HO2 heterogeneous uptake can simultaneously reproduce the OH and HO2 concentrations when the amount of X changed from 0.1 to 0.25 ppb. The ROx primary production rate was dominated by photolysis reactions, in which the HONO, O-3, HCHO, and carbonyls photolysis accounted for 29 %, 16 %, 16 %, and 11 % during the daytime, respectively. The ROx termination rate was dominated by the reaction of OH+NO2 in the morning, and thereafter the radical self-combination gradually became the major sink of ROx in the afternoon. As the sum of the respective oxidation rates of the pollutants via reactions with oxidants, the atmospheric oxidation capacity was evaluated, with a peak of 11.8 ppb h(-1) around noontime. The ratio of P(O-3)(net) to AOC(VOCs), which indicates the yield of net ozone production from VOC oxidation, trended to increase and then decrease as the NO concentration increased. The median ratios ranged within 1.0-4.5, with the maximum existing when the NO concentration was approximately 1 ppb. The nonlinear relationship between the yield of net ozone production from VOC oxidation and NO concentrations demonstrated that optimizing the NOx and VOC control strategies is critical to controlling ozone pollution effectively in the future.
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:000858939800001
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/273771
作者单位	Peking University; Peking University; Helmholtz Association; Research Center Julich; Sun Yat Sen University; Peking University; University Town of Shenzhen
推荐引用方式 GB/T 7714	Yang, Xinping,Lu, Keding,Ma, Xuefei,et al. Radical chemistry in the Pearl River Delta: observations and modeling of OH and HO2 radicals in Shenzhen in 2018[J],2022,22(18):18.
APA	Yang, Xinping.,Lu, Keding.,Ma, Xuefei.,Gao, Yue.,Tan, Zhaofeng.,...&Zhang, Yuanhang.(2022).Radical chemistry in the Pearl River Delta: observations and modeling of OH and HO2 radicals in Shenzhen in 2018.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(18),18.
MLA	Yang, Xinping,et al."Radical chemistry in the Pearl River Delta: observations and modeling of OH and HO2 radicals in Shenzhen in 2018".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.18(2022):18.