Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity
The role of different sources and sinks of CH4 in changes in atmospheric methane ([CH4]) concentration during the last 100 000 yr is still not fully understood. In particular, the magnitude of the change in wetland CH4 emissions at the Last Glacial Maximum (LGM) relative to the pre-industrial period...
Published in: | Climate of the Past |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/cp-9-149-2013 https://cp.copernicus.org/articles/9/149/2013/ |
id |
fttriple:oai:gotriple.eu:4gkHoWHKM36hjcSTsvCjj |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:4gkHoWHKM36hjcSTsvCjj 2023-05-15T16:39:06+02:00 Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity Ringeval, B. Hopcroft, P. O. Valdes, P. J. Ciais, P. Ramstein, G. Dolman, A. J. Kageyama, M. 2018-09-27 https://doi.org/10.5194/cp-9-149-2013 https://cp.copernicus.org/articles/9/149/2013/ en eng Copernicus Publications doi:10.5194/cp-9-149-2013 10670/1.68irlr 1814-9324 1814-9332 https://cp.copernicus.org/articles/9/149/2013/ undefined Geographica Helvetica - geography eISSN: 1814-9332 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/cp-9-149-2013 2023-01-22T17:39:14Z The role of different sources and sinks of CH4 in changes in atmospheric methane ([CH4]) concentration during the last 100 000 yr is still not fully understood. In particular, the magnitude of the change in wetland CH4 emissions at the Last Glacial Maximum (LGM) relative to the pre-industrial period (PI), as well as during abrupt climatic warming or Dansgaard–Oeschger (D–O) events of the last glacial period, is largely unconstrained. In the present study, we aim to understand the uncertainties related to the parameterization of the wetland CH4 emission models relevant to these time periods by using two wetland models of different complexity (SDGVM and ORCHIDEE). These models have been forced by identical climate fields from low-resolution coupled atmosphere–ocean general circulation model (FAMOUS) simulations of these time periods. Both emission models simulate a large decrease in emissions during LGM in comparison to PI consistent with ice core observations and previous modelling studies. The global reduction is much larger in ORCHIDEE than in SDGVM (respectively −67 and −46%), and whilst the differences can be partially explained by different model sensitivities to temperature, the major reason for spatial differences between the models is the inclusion of freezing of soil water in ORCHIDEE and the resultant impact on methanogenesis substrate availability in boreal regions. Besides, a sensitivity test performed with ORCHIDEE in which the methanogenesis substrate sensitivity to the precipitations is modified to be more realistic gives a LGM reduction of −36%. The range of the global LGM decrease is still prone to uncertainty, and here we underline its sensitivity to different process parameterizations. Over the course of an idealized D–O warming, the magnitude of the change in wetland CH4 emissions simulated by the two models at global scale is very similar at around 15 Tg yr−1, but this is only around 25% of the ice-core measured changes in [CH4]. The two models do show regional differences in emission ... Article in Journal/Newspaper ice core Unknown Climate of the Past 9 1 149 171 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
envir geo |
spellingShingle |
envir geo Ringeval, B. Hopcroft, P. O. Valdes, P. J. Ciais, P. Ramstein, G. Dolman, A. J. Kageyama, M. Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity |
topic_facet |
envir geo |
description |
The role of different sources and sinks of CH4 in changes in atmospheric methane ([CH4]) concentration during the last 100 000 yr is still not fully understood. In particular, the magnitude of the change in wetland CH4 emissions at the Last Glacial Maximum (LGM) relative to the pre-industrial period (PI), as well as during abrupt climatic warming or Dansgaard–Oeschger (D–O) events of the last glacial period, is largely unconstrained. In the present study, we aim to understand the uncertainties related to the parameterization of the wetland CH4 emission models relevant to these time periods by using two wetland models of different complexity (SDGVM and ORCHIDEE). These models have been forced by identical climate fields from low-resolution coupled atmosphere–ocean general circulation model (FAMOUS) simulations of these time periods. Both emission models simulate a large decrease in emissions during LGM in comparison to PI consistent with ice core observations and previous modelling studies. The global reduction is much larger in ORCHIDEE than in SDGVM (respectively −67 and −46%), and whilst the differences can be partially explained by different model sensitivities to temperature, the major reason for spatial differences between the models is the inclusion of freezing of soil water in ORCHIDEE and the resultant impact on methanogenesis substrate availability in boreal regions. Besides, a sensitivity test performed with ORCHIDEE in which the methanogenesis substrate sensitivity to the precipitations is modified to be more realistic gives a LGM reduction of −36%. The range of the global LGM decrease is still prone to uncertainty, and here we underline its sensitivity to different process parameterizations. Over the course of an idealized D–O warming, the magnitude of the change in wetland CH4 emissions simulated by the two models at global scale is very similar at around 15 Tg yr−1, but this is only around 25% of the ice-core measured changes in [CH4]. The two models do show regional differences in emission ... |
format |
Article in Journal/Newspaper |
author |
Ringeval, B. Hopcroft, P. O. Valdes, P. J. Ciais, P. Ramstein, G. Dolman, A. J. Kageyama, M. |
author_facet |
Ringeval, B. Hopcroft, P. O. Valdes, P. J. Ciais, P. Ramstein, G. Dolman, A. J. Kageyama, M. |
author_sort |
Ringeval, B. |
title |
Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity |
title_short |
Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity |
title_full |
Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity |
title_fullStr |
Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity |
title_full_unstemmed |
Response of methane emissions from wetlands to the Last Glacial Maximum and an idealized Dansgaard–Oeschger climate event: insights from two models of different complexity |
title_sort |
response of methane emissions from wetlands to the last glacial maximum and an idealized dansgaard–oeschger climate event: insights from two models of different complexity |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-9-149-2013 https://cp.copernicus.org/articles/9/149/2013/ |
genre |
ice core |
genre_facet |
ice core |
op_source |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-9-149-2013 10670/1.68irlr 1814-9324 1814-9332 https://cp.copernicus.org/articles/9/149/2013/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-9-149-2013 |
container_title |
Climate of the Past |
container_volume |
9 |
container_issue |
1 |
container_start_page |
149 |
op_container_end_page |
171 |
_version_ |
1766029426605162496 |