Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn
The budgets of seven halogenated gases (CFC-11, CFC-12, CFC-113, CFC-114, CFC-115, CCl 4 and SF 6 ) are studied by comparing measurements in polar firn air from two Arctic and three Antarctic sites, and simulation results of two numerical models: a 2-D atmospheric chemistry model and a 1-D firn diff...
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ftdoajarticles:oai:doaj.org/article:cd3c5fe912b745b281af74a601293616 2023-05-15T13:58:19+02:00 Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn P. Martinerie E. Nourtier-Mazauric J.-M. Barnola W. T. Sturges D. R. Worton E. Atlas L. K. Gohar K. P. Shine G. P. Brasseur 2009-06-01T00:00:00Z https://doaj.org/article/cd3c5fe912b745b281af74a601293616 EN eng Copernicus Publications http://www.atmos-chem-phys.net/9/3911/2009/acp-9-3911-2009.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 https://doaj.org/article/cd3c5fe912b745b281af74a601293616 Atmospheric Chemistry and Physics, Vol 9, Iss 12, Pp 3911-3934 (2009) Physics QC1-999 Chemistry QD1-999 article 2009 ftdoajarticles 2022-12-31T00:39:13Z The budgets of seven halogenated gases (CFC-11, CFC-12, CFC-113, CFC-114, CFC-115, CCl 4 and SF 6 ) are studied by comparing measurements in polar firn air from two Arctic and three Antarctic sites, and simulation results of two numerical models: a 2-D atmospheric chemistry model and a 1-D firn diffusion model. The first one is used to calculate atmospheric concentrations from emission trends based on industrial inventories; the calculated concentration trends are used by the second one to produce depth concentration profiles in the firn. The 2-D atmospheric model is validated in the boundary layer by comparison with atmospheric station measurements, and vertically for CFC-12 by comparison with balloon and FTIR measurements. Firn air measurements provide constraints on historical atmospheric concentrations over the last century. Age distributions in the firn are discussed using a Green function approach. Finally, our results are used as input to a radiative model in order to evaluate the radiative forcing of our target gases. Multi-species and multi-site firn air studies allow to better constrain atmospheric trends. The low concentrations of all studied gases at the bottom of the firn, and their consistency with our model results confirm that their natural sources are small. Our results indicate that the emissions, sinks and trends of CFC-11, CFC-12, CFC-113, CFC-115 and SF 6 are well constrained, whereas it is not the case for CFC-114 and CCl 4 . Significant emission-dependent changes in the lifetimes of halocarbons destroyed in the stratosphere were obtained. Those result from the time needed for their transport from the surface where they are emitted to the stratosphere where they are destroyed. Efforts should be made to update and reduce the large uncertainties on CFC lifetimes. Article in Journal/Newspaper Antarc* Antarctic Arctic Directory of Open Access Journals: DOAJ Articles Antarctic Arctic |
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 P. Martinerie E. Nourtier-Mazauric J.-M. Barnola W. T. Sturges D. R. Worton E. Atlas L. K. Gohar K. P. Shine G. P. Brasseur Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
The budgets of seven halogenated gases (CFC-11, CFC-12, CFC-113, CFC-114, CFC-115, CCl 4 and SF 6 ) are studied by comparing measurements in polar firn air from two Arctic and three Antarctic sites, and simulation results of two numerical models: a 2-D atmospheric chemistry model and a 1-D firn diffusion model. The first one is used to calculate atmospheric concentrations from emission trends based on industrial inventories; the calculated concentration trends are used by the second one to produce depth concentration profiles in the firn. The 2-D atmospheric model is validated in the boundary layer by comparison with atmospheric station measurements, and vertically for CFC-12 by comparison with balloon and FTIR measurements. Firn air measurements provide constraints on historical atmospheric concentrations over the last century. Age distributions in the firn are discussed using a Green function approach. Finally, our results are used as input to a radiative model in order to evaluate the radiative forcing of our target gases. Multi-species and multi-site firn air studies allow to better constrain atmospheric trends. The low concentrations of all studied gases at the bottom of the firn, and their consistency with our model results confirm that their natural sources are small. Our results indicate that the emissions, sinks and trends of CFC-11, CFC-12, CFC-113, CFC-115 and SF 6 are well constrained, whereas it is not the case for CFC-114 and CCl 4 . Significant emission-dependent changes in the lifetimes of halocarbons destroyed in the stratosphere were obtained. Those result from the time needed for their transport from the surface where they are emitted to the stratosphere where they are destroyed. Efforts should be made to update and reduce the large uncertainties on CFC lifetimes. |
format |
Article in Journal/Newspaper |
author |
P. Martinerie E. Nourtier-Mazauric J.-M. Barnola W. T. Sturges D. R. Worton E. Atlas L. K. Gohar K. P. Shine G. P. Brasseur |
author_facet |
P. Martinerie E. Nourtier-Mazauric J.-M. Barnola W. T. Sturges D. R. Worton E. Atlas L. K. Gohar K. P. Shine G. P. Brasseur |
author_sort |
P. Martinerie |
title |
Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
title_short |
Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
title_full |
Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
title_fullStr |
Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
title_full_unstemmed |
Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
title_sort |
long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
publisher |
Copernicus Publications |
publishDate |
2009 |
url |
https://doaj.org/article/cd3c5fe912b745b281af74a601293616 |
geographic |
Antarctic Arctic |
geographic_facet |
Antarctic Arctic |
genre |
Antarc* Antarctic Arctic |
genre_facet |
Antarc* Antarctic Arctic |
op_source |
Atmospheric Chemistry and Physics, Vol 9, Iss 12, Pp 3911-3934 (2009) |
op_relation |
http://www.atmos-chem-phys.net/9/3911/2009/acp-9-3911-2009.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 https://doaj.org/article/cd3c5fe912b745b281af74a601293616 |
_version_ |
1766266544908664832 |