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 (O 3 ). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl 2 F 2 , Laube et al.,...
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ftdoajarticles:oai:doaj.org/article:2229c459e36b4c8480b3e27ca2180d15 2023-05-15T13:37:12+02:00 Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air S. J. Allin J. C. Laube E. Witrant J. Kaiser E. McKenna P. Dennis R. Mulvaney E. Capron P. Martinerie T. Röckmann T. Blunier J. Schwander P. J. Fraser R. L. Langenfelds W. T. Sturges 2015-06-01T00:00:00Z https://doi.org/10.5194/acp-15-6867-2015 https://doaj.org/article/2229c459e36b4c8480b3e27ca2180d15 EN eng Copernicus Publications http://www.atmos-chem-phys.net/15/6867/2015/acp-15-6867-2015.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-15-6867-2015 https://doaj.org/article/2229c459e36b4c8480b3e27ca2180d15 Atmospheric Chemistry and Physics, Vol 15, Iss 12, Pp 6867-6877 (2015) Physics QC1-999 Chemistry QD1-999 article 2015 ftdoajarticles https://doi.org/10.5194/acp-15-6867-2015 2022-12-31T05:50:18Z The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O 3 ). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl 2 F 2 , Laube et al., 2010a), similar to effects seen in nitrous oxide (N 2 O). 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 (CCl 3 F) and CFC-113 (CClF 2 CCl 2 F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ε app ) 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 37 Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ ( 37 Cl) 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 ... Article in Journal/Newspaper Antarc* Antarctica Greenland North Greenland Directory of Open Access Journals: DOAJ Articles 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 |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 S. J. Allin J. C. Laube E. Witrant J. Kaiser E. McKenna P. Dennis R. Mulvaney E. Capron P. Martinerie T. Röckmann T. Blunier J. Schwander P. J. Fraser R. L. Langenfelds W. T. Sturges Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O 3 ). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl 2 F 2 , Laube et al., 2010a), similar to effects seen in nitrous oxide (N 2 O). 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 (CCl 3 F) and CFC-113 (CClF 2 CCl 2 F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (ε app ) 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 37 Cl enrichment and stratosphere–troposphere exchange. We compare these projections to the long-term δ ( 37 Cl) 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 ... |
format |
Article in Journal/Newspaper |
author |
S. J. Allin J. C. Laube E. Witrant J. Kaiser E. McKenna P. Dennis R. Mulvaney E. Capron P. Martinerie T. Röckmann T. Blunier J. Schwander P. J. Fraser R. L. Langenfelds W. T. Sturges |
author_facet |
S. J. Allin J. C. Laube E. Witrant J. Kaiser E. McKenna P. Dennis R. Mulvaney E. Capron P. Martinerie T. Röckmann T. Blunier J. Schwander P. J. Fraser R. L. Langenfelds W. T. Sturges |
author_sort |
S. J. Allin |
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 |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/acp-15-6867-2015 https://doaj.org/article/2229c459e36b4c8480b3e27ca2180d15 |
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 |
Atmospheric Chemistry and Physics, Vol 15, Iss 12, Pp 6867-6877 (2015) |
op_relation |
http://www.atmos-chem-phys.net/15/6867/2015/acp-15-6867-2015.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-15-6867-2015 https://doaj.org/article/2229c459e36b4c8480b3e27ca2180d15 |
op_doi |
https://doi.org/10.5194/acp-15-6867-2015 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
15 |
container_issue |
12 |
container_start_page |
6867 |
op_container_end_page |
6877 |
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1766089157198741504 |