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...
Published in: | Atmospheric Chemistry and Physics |
---|---|
Main Authors: | , , , , , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/acp-9-3911-2009 https://www.atmos-chem-phys.net/9/3911/2009/ |
id |
ftcopernicus:oai:publications.copernicus.org:acp5569 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:acp5569 2023-05-15T13:45:55+02:00 Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn Martinerie, P. Nourtier-Mazauric, E. Barnola, J.-M. Sturges, W. T. Worton, D. R. Atlas, E. Gohar, L. K. Shine, K. P. Brasseur, G. P. 2018-01-15 application/pdf https://doi.org/10.5194/acp-9-3911-2009 https://www.atmos-chem-phys.net/9/3911/2009/ eng eng doi:10.5194/acp-9-3911-2009 https://www.atmos-chem-phys.net/9/3911/2009/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-9-3911-2009 2019-12-24T09:57:52Z 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. Text Antarc* Antarctic Arctic Copernicus Publications: E-Journals Antarctic Arctic Atmospheric Chemistry and Physics 9 12 3911 3934 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
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 |
Text |
author |
Martinerie, P. Nourtier-Mazauric, E. Barnola, J.-M. Sturges, W. T. Worton, D. R. Atlas, E. Gohar, L. K. Shine, K. P. Brasseur, G. P. |
spellingShingle |
Martinerie, P. Nourtier-Mazauric, E. Barnola, J.-M. Sturges, W. T. Worton, D. R. Atlas, E. Gohar, L. K. Shine, K. P. Brasseur, G. P. Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn |
author_facet |
Martinerie, P. Nourtier-Mazauric, E. Barnola, J.-M. Sturges, W. T. Worton, D. R. Atlas, E. Gohar, L. K. Shine, K. P. Brasseur, G. P. |
author_sort |
Martinerie, P. |
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 |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-9-3911-2009 https://www.atmos-chem-phys.net/9/3911/2009/ |
geographic |
Antarctic Arctic |
geographic_facet |
Antarctic Arctic |
genre |
Antarc* Antarctic Arctic |
genre_facet |
Antarc* Antarctic Arctic |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-9-3911-2009 https://www.atmos-chem-phys.net/9/3911/2009/ |
op_doi |
https://doi.org/10.5194/acp-9-3911-2009 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
9 |
container_issue |
12 |
container_start_page |
3911 |
op_container_end_page |
3934 |
_version_ |
1766232648996356096 |