气候变化领域集成服务门户(CCPortal): Tropospheric OH and stratospheric OH and Cl concentrations determined from CH4, CH3Cl, and SF6 measurements

CCPortal

DOI	10.1038/s41612-018-0041-9
	Tropospheric OH and stratospheric OH and Cl concentrations determined from CH4, CH3Cl, and SF6 measurements
	Li M.; Karu E.; Brenninkmeijer C.; Fischer H.; Lelieveld J.; Williams J.
发表日期	2018
ISSN	23973722
卷号	1 期号:1
英文摘要	The hydroxyl (OH) radical is the key oxidant in the global atmosphere as it controls the concentrations of toxic gases like carbon monoxide and climate relevant gases like methane. In some regions, oxidation by chlorine (Cl) radical is also important, and in the stratosphere both OH and Cl radicals impact ozone. An empirical method is presented to determine effective OH concentrations in the troposphere and lower stratosphere, based on CH4, CH3Cl, and SF6 data from aircraft measurements (IAGOS-CARIBIC) and a ground-based station (NOAA). Tropospheric OH average values of 10.9 × 105 (σ = 9.6 × 105) molecules cm−3 and stratospheric OH average values of 1.1 × 105 (σ = 0.8 × 105) molecules cm−3 were derived over mean ages derived from SF6. Using CH4 led to higher OH estimates due to the temperature dependence of the CH4 + OH reaction in the troposphere and due to the presence of Cl in the stratosphere. Exploiting the difference in effective OH calculated from CH3Cl and CH4 we determine the main altitude for tropospheric CH4 oxidation to be 4.5 ~ 10.5 km and the average Cl radical concentration in the lower stratosphere to be 1.1 × 104 (σ = 0.6 × 104) molecules cm−3 (with a 35% measurement uncertainty). Furthermore, the data are used to examine the temporal trend in annual average stratospheric OH and Cl radical concentrations between 2010 and 2015. The year 2013 showed highest stratospheric OH and lowest Cl but no clear temporal trend was observed in the data in this period. These data serve as a baseline for future studies of stratospheric circulation changes. © 2018, The Author(s).
语种	英语
scopus关键词	atmospheric chemistry; atmospheric circulation; chlorine; concentration (composition); hydroxyl radical; methane; molecular analysis; oxidation; stratosphere; stratosphere-troposphere interaction
来源期刊	npj Climate and Atmospheric Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178188
作者单位	Max Planck Institute for Chemistry, Mainz, 55128, Germany
推荐引用方式 GB/T 7714	Li M.,Karu E.,Brenninkmeijer C.,et al. Tropospheric OH and stratospheric OH and Cl concentrations determined from CH4, CH3Cl, and SF6 measurements[J],2018,1(1).
APA	Li M.,Karu E.,Brenninkmeijer C.,Fischer H.,Lelieveld J.,&Williams J..(2018).Tropospheric OH and stratospheric OH and Cl concentrations determined from CH4, CH3Cl, and SF6 measurements.npj Climate and Atmospheric Science,1(1).
MLA	Li M.,et al."Tropospheric OH and stratospheric OH and Cl concentrations determined from CH4, CH3Cl, and SF6 measurements".npj Climate and Atmospheric Science 1.1(2018).