气候变化领域集成服务门户(CCPortal): Stratospheric carbon isotope fractionation and tropospheric histories of CFC-11, CFC-12, and CFC-113 isotopologues

CCPortal

DOI	10.5194/acp-21-6857-2021
	Stratospheric carbon isotope fractionation and tropospheric histories of CFC-11, CFC-12, and CFC-113 isotopologues
	Thomas M.; Laube J.C.; Kaiser J.; Allin S.; Martinerie P.; Mulvaney R.; Ridley A.; Röckmann T.; Sturges W.T.; Witrant E.
发表日期	2021
ISSN	1680-7316
起始页码	6857
结束页码	6873
卷号	21 期号:9
英文摘要	We present novel measurements of the carbon isotope composition of CFC-11 (CCl3F), CFC-12 (CCl2F2), and CFC-113 (CF2ClCFCl2), three atmospheric trace gases that are important for both stratospheric ozone depletion and global warming. These measurements were carried out on air samples collected in the stratosphere the main sink region for these gases and on air extracted from deep polar firn snow. We quantify, for the first time, the apparent isotopic fractionation, ?app(13C), for these gases as they are destroyed in the high- and mid-latitude stratosphere: ?app(CFC-12, high-latitude)?=(-20.2 4.4)? , and ?app(CFC-113, high-latitude)?=(-9.4 4.4)? , ?app(CFC-12, mid-latitude)?=(-30.3 10.7)? , and ?app(CFC-113, mid-latitude)?=(-34.4 9.8)? . Our CFC-11 measurements were not sufficient to calculate ?app(CFC-11), so we instead used previously reported photolytic fractionation for CFC-11 and CFC-12 to scale our ?app(CFC-12), resulting in ?app(CFC-11, high-latitude)?=(-7.8 1.7)? and ?app(CFC-11, mid-latitude)?=(-11.7 4.2)? . Measurements of firn air were used to construct histories of the tropospheric isotopic composition, dT(13C), for CFC-11 (1950s to 2009), CFC-12 (1950s to 2009), and CFC-113 (1970s to 2009), with dT(13C) increasing for each gas. We used ?app(high-latitude), which was derived from more data, and a constant isotopic composition of emissions, dE(13C), to model dT(13C, CFC-11), dT(13C, CFC-12), and dT(13C, CFC-113). For CFC-11 and CFC-12, modelled dT(13C) was consistent with measured dT(13C) for the entire period covered by the measurements, suggesting that no dramatic change in dE(13C, CFC-11) or dE(13C, CFC-12) has occurred since the 1950s. For CFC-113, our modelled dT(13C, CFC-113) did not agree with our measurements earlier than 1980. This discrepancy may be indicative of a change in dE(13C, CFC-113). However, this conclusion is based largely on a single sample and only just significant outside the 95?% confidence interval. Therefore more work is needed to independently verify this temporal trend in the global tropospheric 13C isotopic composition of CFC-113. Our modelling predicts increasing dT(13C, CFC-11), dT(13C, CFC-12), and dT(13C, CFC-113) into the future. We investigated the effect of recently reported new CFC-11 emissions on background dT(13C, CFC-11) by fixing model emissions after 2012 and comparing dT(13C, CFC-11) in this scenario to the model base case. The difference in dT(13C, CFC-11) between these scenarios was 1.4? in 2050. This difference is smaller than our model uncertainty envelope and would therefore require improved modelling and measurement precision as well as better quantified isotopic source compositions to detect. © 2021 Elsevier Ltd. All rights reserved.
语种	英语
scopus关键词	atmospheric chemistry; carbon isotope; isotopic fractionation; stratosphere; trace gas; 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/246918
作者单位	Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom; Institute of Energy and Climate Research - Stratosphere (IEK-7), Forschungszentrum Julich GmbHJ, Julich, Germany; Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble, 38000, France; British Antarctic Survey, Cambridge, United Kingdom; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands; Universite Grenoble Alpes, CNRS, Grenoble Image Parole Signal Automatique (GIPSA-Lab), Grenoble, France; Department of Physics, University of Otago, Dunedin, New Zealand
推荐引用方式 GB/T 7714	Thomas M.,Laube J.C.,Kaiser J.,et al. Stratospheric carbon isotope fractionation and tropospheric histories of CFC-11, CFC-12, and CFC-113 isotopologues[J],2021,21(9).
APA	Thomas M..,Laube J.C..,Kaiser J..,Allin S..,Martinerie P..,...&Witrant E..(2021).Stratospheric carbon isotope fractionation and tropospheric histories of CFC-11, CFC-12, and CFC-113 isotopologues.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(9).
MLA	Thomas M.,et al."Stratospheric carbon isotope fractionation and tropospheric histories of CFC-11, CFC-12, and CFC-113 isotopologues".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.9(2021).