气候变化领域集成服务门户(CCPortal): Experimental chemical budgets of OH, HO2, and RO2 radicals in ruralair in western Germany during the JULIAC campaign 2019

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DOI	10.5194/acp-23-2003-2023
	Experimental chemical budgets of OH, HO2, and RO2 radicals in ruralair in western Germany during the JULIAC campaign 2019
	Cho, Changmin; Fuchs, Hendrik; Hofzumahaus, Andreas; Holland, Frank; Bloss, William J.; Bohn, Birger; Dorn, Hans-Peter; Glowania, Marvin; Hohaus, Thorsten; Liu, Lu; Monks, Paul S.; Niether, Doreen; Rohrer, Franz; Sommariva, Roberto; Tan, Zhaofeng; Tillmann, Ralf; Kiendler-Scharr, Astrid; Wahner, Andreas; Novelli, Anna
发表日期	2023
ISSN	1680-7316
EISSN	1680-7324
起始页码	2003
结束页码	2033
卷号	23 期号:3 页码:31
英文摘要	Photochemical processes in ambient air were studied using the atmospheric simulation chamber SAPHIR at Forschungszentrum Julich, Germany. Ambient air was continuously drawn into the chamber through a 50 m high inlet line and passed through the chamber for 1 month in each season throughout 2019. The residence time of the air inside the chamber was about 1 h. As the research center is surrounded by a mixed deciduous forest and is located close to the city Julich, the sampled air was influenced by both anthropogenic and biogenic emissions. Measurements of hydroxyl (OH), hydroperoxyl (HO2), and organic peroxy (RO2) radicals were achieved by a laser-induced fluorescence instrument. The radical measurements together with measurements of OH reactivity (kOH, the inverse of the OH lifetime) and a comprehensive set of trace gas concentrations and aerosol properties allowed for the investigation of the seasonal and diurnal variation of radical production and destruction pathways. In spring and summer periods, median OH concentrations reached 6 x 10(6) cm(-3) at noon, and median concentrations of both HO2 and RO2 radicals were 3 x 10(8) cm(-3). The measured OH reactivity was between 4 and 18 s(-1) in both seasons. The total reaction rate of peroxy radicals with NO was found to be consistent with production rates of odd oxygen (O-x= NO2+ O-3) determined from NO2 and O-3 concentration measurements. The chemical budgets of radicals were analyzed for the spring and summer seasons, when peroxy radical concentrations were above the detection limit. For most conditions, the concentrations of radicals were mainly sustained by the regeneration of OH via reactions of HO2 and RO2 radicals with nitric oxide (NO). The median diurnal profiles of the total radical production and destruction rates showed maxima between 3 and 6 ppbv h(-1) for OH, HO2, and RO2. Total ROX (OH, HO2, and RO2) initiation and termination rates were below 3 ppbv h(-1). The highest OH radical turnover rate of 13 ppbv h(-1) was observed during a high-temperature (max. 40 ?) period in August. In this period, the highest HO2, RO2, and ROX turnover rates were around 11, 10, and 4 ppbv h(-1), respectively. When NO mixing ratios were between 1 and 3 ppbv, OH and HO2 production and destruction rates were balanced, but unexplained RO2 and ROX production reactions with median rates of 2 and 0.4 ppbv h(-1), respectively, were required to balance their destruction. For NO mixing ratios above 3 ppbv, the peroxy radical reaction rates with NO were highly uncertain due to the low peroxy radical concentrations close to the limit of NO interferences in the HO2 and RO2 measurements. For NO mixing ratios below 1 ppbv, a missing source for OH and a missing sink for HO2 were found with maximum rates of 3.0 and 2.0 ppbv h(-1), respectively. The missing OH source likely consisted of a combination of a missing inter-radical HO2 to OH conversion reaction (up to 2 ppbv h(-1)) and a missing primary radical source (0.5-1.4 ppbv h(-1)). The dataset collected in this campaign allowed analyzing the potential impact of OH regeneration from RO2 isomerization reactions from isoprene, HO2 uptake on aerosol, and RO2 production from chlorine chemistry on radical production and destruction rates. These processes were negligible for the chemical conditions encountered 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:000931124700001
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/273759
作者单位	Helmholtz Association; Research Center Julich; University of Leicester; Gwangju Institute of Science & Technology (GIST)
推荐引用方式 GB/T 7714	Cho, Changmin,Fuchs, Hendrik,Hofzumahaus, Andreas,et al. Experimental chemical budgets of OH, HO2, and RO2 radicals in ruralair in western Germany during the JULIAC campaign 2019[J],2023,23(3):31.
APA	Cho, Changmin.,Fuchs, Hendrik.,Hofzumahaus, Andreas.,Holland, Frank.,Bloss, William J..,...&Novelli, Anna.(2023).Experimental chemical budgets of OH, HO2, and RO2 radicals in ruralair in western Germany during the JULIAC campaign 2019.ATMOSPHERIC CHEMISTRY AND PHYSICS,23(3),31.
MLA	Cho, Changmin,et al."Experimental chemical budgets of OH, HO2, and RO2 radicals in ruralair in western Germany during the JULIAC campaign 2019".ATMOSPHERIC CHEMISTRY AND PHYSICS 23.3(2023):31.