气候变化领域集成服务门户(CCPortal): Quantifying the nitrogen isotope effects during photochemical equilibrium between NO and NO2: Implications for δ15N in tropospheric reactive nitrogen

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DOI	10.5194/acp-20-9805-2020
	Quantifying the nitrogen isotope effects during photochemical equilibrium between NO and NO2: Implications for δ15N in tropospheric reactive nitrogen
	Li J.; Zhang X.; Orlando J.; Tyndall G.; Michalski G.
发表日期	2020
ISSN	1680-7316
起始页码	9805
结束页码	9819
卷号	20 期号:16
英文摘要	Nitrogen isotope fractionations between nitrogen oxides (NO and NO2) play a significant role in determining the nitrogen isotopic compositions (15N) of atmospheric reactive nitrogen. Both the equilibrium isotopic exchange between NO and NO2 molecules and the isotope effects occurring during the NOx photochemical cycle are important, but both are not well constrained. The nighttime and daytime isotopic fractionations between NO and NO2 in an atmospheric simulation chamber at atmospherically relevant NOx evels were measured. Then, the impact of NOx level and O2 photolysis rate on the combined isotopic fractionation (equilibrium isotopic exchange and photochemical cycle) between O and NO2 was calculated. It was found that the isotope effects occurring during the NOx photochemical cycle can be described using a single fractionation factor, designated the Leighton cycle isotope effect (LCIE). The results howed that at room temperature, the fractionation factor of nitrogen isotopic exchange is 1:02890:0019, and the fractionation factor of LCIE (when O3 solely controls the oxidation from NO to NO2) is 0:9900:005. The measured LCIE factor showed good agreement with previous field measurements, suggesting that it could be applied in an ambient environment, although future work is needed to assess the isotopic fractionation factors of NOCRO2=HO2!NO2. The esults were used to model the NOaNO2 isotopic fractionations under several NOx conditions. The model suggested hat isotopic exchange was the dominant factor when NOx > 20 nmol mol 1, while LCIE was more important at low NOx concentrations (< 1 nmol mol 1) and high rates of NO2 photolysis. These findings provided a useful tool to quantify the isotopic fractionations between tropospheric NO and NO2, which can be applied in future field observations and atmospheric chemistry models. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	atmospheric chemistry; atmospheric modeling; concentration (composition); isotopic composition; nitric oxide; nitrogen dioxide; nitrogen isotope; photochemistry; quantitative analysis; reactive transport; troposphere
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/141146
作者单位	Department of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, IN 47907, United States; Atmospheric Chemistry Observations and Modeling Lab, National Center for Atmospheric Research, Boulder, CO 80301, United States; Department of Chemistry, Purdue University, West Lafayette, IN 47907, United States
推荐引用方式 GB/T 7714	Li J.,Zhang X.,Orlando J.,et al. Quantifying the nitrogen isotope effects during photochemical equilibrium between NO and NO2: Implications for δ15N in tropospheric reactive nitrogen[J],2020,20(16).
APA	Li J.,Zhang X.,Orlando J.,Tyndall G.,&Michalski G..(2020).Quantifying the nitrogen isotope effects during photochemical equilibrium between NO and NO2: Implications for δ15N in tropospheric reactive nitrogen.Atmospheric Chemistry and Physics,20(16).
MLA	Li J.,et al."Quantifying the nitrogen isotope effects during photochemical equilibrium between NO and NO2: Implications for δ15N in tropospheric reactive nitrogen".Atmospheric Chemistry and Physics 20.16(2020).