Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air
The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a...
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ftunivbern:oai:boris.unibe.ch:74358 2023-08-20T04:00:59+02:00 Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air Allin, S. J. Laube, J. C. Witrant, E. Kaiser, J. McKenna, E. Dennis, P. Mulvaney, R. Capron, E. Martinerie, P. Röckmann, T. Blunier, Thomas Schwander, J. Fraser, P. J. Langenfelds, R. L. Sturges, W. T. 2015 application/pdf https://boris.unibe.ch/74358/1/allin15acp.pdf https://boris.unibe.ch/74358/ eng eng European Geosciences Union https://boris.unibe.ch/74358/ info:eu-repo/semantics/openAccess Allin, S. J.; Laube, J. C.; Witrant, E.; Kaiser, J.; McKenna, E.; Dennis, P.; Mulvaney, R.; Capron, E.; Martinerie, P.; Röckmann, T.; Blunier, Thomas; Schwander, J.; Fraser, P. J.; Langenfelds, R. L.; Sturges, W. T. (2015). Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air. Atmospheric chemistry and physics, 15(12), pp. 6867-6877. European Geosciences Union 10.5194/acp-15-6867-2015 <http://dx.doi.org/10.5194/acp-15-6867-2015> 530 Physics info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2015 ftunivbern https://doi.org/10.5194/acp-15-6867-2015 2023-07-31T21:21:35Z The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ϵapp) for mid- and high-latitude stratospheric samples are respectively −2.4 (0.5) and −2.3 (0.4) ‰ for CFC-11, −12.2 (1.6) and −6.8 (0.8) ‰ for CFC-12 and −3.5 (1.5) and −3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of the standard uncertainty expressed in per mil. Assuming a constant isotope composition of emissions, we calculate the expected trends in the tropospheric isotope signature of these gases based on their stratospheric 37Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ (37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978–2010) and tropospheric firn air samples from Greenland (North Greenland Eemian Ice Drilling (NEEM) site) and Antarctica (Fletcher Promontory site). From 1970 to the present day, projected trends agree with tropospheric measurements, suggesting that within analytical uncertainties, a constant average emission isotope delta (δ) is a compatible scenario. The measurement uncertainty is too high to determine whether the average emission isotope δ has been affected by changes in CFC manufacturing processes or not. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes ... Article in Journal/Newspaper Antarc* Antarctica Greenland North Greenland BORIS (Bern Open Repository and Information System, University of Bern) Fletcher Promontory ENVELOPE(-80.000,-80.000,-78.416,-78.416) Greenland Grim ENVELOPE(-64.486,-64.486,-65.379,-65.379) Atmospheric Chemistry and Physics 15 12 6867 6877 |
institution |
Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
530 Physics |
spellingShingle |
530 Physics Allin, S. J. Laube, J. C. Witrant, E. Kaiser, J. McKenna, E. Dennis, P. Mulvaney, R. Capron, E. Martinerie, P. Röckmann, T. Blunier, Thomas Schwander, J. Fraser, P. J. Langenfelds, R. L. Sturges, W. T. Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
topic_facet |
530 Physics |
description |
The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ϵapp) for mid- and high-latitude stratospheric samples are respectively −2.4 (0.5) and −2.3 (0.4) ‰ for CFC-11, −12.2 (1.6) and −6.8 (0.8) ‰ for CFC-12 and −3.5 (1.5) and −3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of the standard uncertainty expressed in per mil. Assuming a constant isotope composition of emissions, we calculate the expected trends in the tropospheric isotope signature of these gases based on their stratospheric 37Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ (37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978–2010) and tropospheric firn air samples from Greenland (North Greenland Eemian Ice Drilling (NEEM) site) and Antarctica (Fletcher Promontory site). From 1970 to the present day, projected trends agree with tropospheric measurements, suggesting that within analytical uncertainties, a constant average emission isotope delta (δ) is a compatible scenario. The measurement uncertainty is too high to determine whether the average emission isotope δ has been affected by changes in CFC manufacturing processes or not. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes ... |
format |
Article in Journal/Newspaper |
author |
Allin, S. J. Laube, J. C. Witrant, E. Kaiser, J. McKenna, E. Dennis, P. Mulvaney, R. Capron, E. Martinerie, P. Röckmann, T. Blunier, Thomas Schwander, J. Fraser, P. J. Langenfelds, R. L. Sturges, W. T. |
author_facet |
Allin, S. J. Laube, J. C. Witrant, E. Kaiser, J. McKenna, E. Dennis, P. Mulvaney, R. Capron, E. Martinerie, P. Röckmann, T. Blunier, Thomas Schwander, J. Fraser, P. J. Langenfelds, R. L. Sturges, W. T. |
author_sort |
Allin, S. J. |
title |
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
title_short |
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
title_full |
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
title_fullStr |
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
title_full_unstemmed |
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
title_sort |
chlorine isotope composition in chlorofluorocarbons cfc-11, cfc-12 and cfc-113 in firn, stratospheric and tropospheric air |
publisher |
European Geosciences Union |
publishDate |
2015 |
url |
https://boris.unibe.ch/74358/1/allin15acp.pdf https://boris.unibe.ch/74358/ |
long_lat |
ENVELOPE(-80.000,-80.000,-78.416,-78.416) ENVELOPE(-64.486,-64.486,-65.379,-65.379) |
geographic |
Fletcher Promontory Greenland Grim |
geographic_facet |
Fletcher Promontory Greenland Grim |
genre |
Antarc* Antarctica Greenland North Greenland |
genre_facet |
Antarc* Antarctica Greenland North Greenland |
op_source |
Allin, S. J.; Laube, J. C.; Witrant, E.; Kaiser, J.; McKenna, E.; Dennis, P.; Mulvaney, R.; Capron, E.; Martinerie, P.; Röckmann, T.; Blunier, Thomas; Schwander, J.; Fraser, P. J.; Langenfelds, R. L.; Sturges, W. T. (2015). Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air. Atmospheric chemistry and physics, 15(12), pp. 6867-6877. European Geosciences Union 10.5194/acp-15-6867-2015 <http://dx.doi.org/10.5194/acp-15-6867-2015> |
op_relation |
https://boris.unibe.ch/74358/ |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/acp-15-6867-2015 |
container_title |
Atmospheric Chemistry and Physics |
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15 |
container_issue |
12 |
container_start_page |
6867 |
op_container_end_page |
6877 |
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1774721840369893376 |