Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model
We examine several aspects of the ocean-atmosphere system over the last 30 000 years, by carrying out simulations with prescribed ice sheets, atmospheric CO 2 concentration, and orbital parameters. We use the GENIE-1 model with a frictional geostrophic ocean, dynamic sea ice, an energy balance atmos...
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ftdoajarticles:oai:doaj.org/article:e1d25875221f4b99a6f7af77c293cc69 2023-05-15T16:39:19+02:00 Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model D. J. Lunt M. S. Williamson P. J. Valdes T. M. Lenton R. Marsh 2006-01-01T00:00:00Z https://doaj.org/article/e1d25875221f4b99a6f7af77c293cc69 EN eng Copernicus Publications http://www.clim-past.net/2/221/2006/cp-2-221-2006.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 https://doaj.org/article/e1d25875221f4b99a6f7af77c293cc69 Climate of the Past, Vol 2, Iss 2, Pp 221-235 (2006) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2006 ftdoajarticles 2022-12-31T09:47:06Z We examine several aspects of the ocean-atmosphere system over the last 30 000 years, by carrying out simulations with prescribed ice sheets, atmospheric CO 2 concentration, and orbital parameters. We use the GENIE-1 model with a frictional geostrophic ocean, dynamic sea ice, an energy balance atmosphere, and a land-surface scheme with fixed vegetation. A transient simulation, with boundary conditions derived from ice-core records and ice sheet reconstructions, is compared with equilibrium snapshot simulations, including the Last Glacial Maximum (21 000 years before present; 21 kyrBP), mid-Holocene (6 kyrBP) and pre-industrial. The equilibrium snapshot simulations are all very similar to their corresponding time period in the transient simulation, indicating that over the last 30 000 years, the model's ocean-atmosphere system is close to equilibrium with its boundary conditions. However, our simulations neglect the transfer of fresh water from and to the ocean, resulting from the growth and decay of ice sheets, which would, in reality, lead to greater disequilibrium. Additionally, the GENIE-1 model exhibits a rather limited response in terms of its Atlantic Meridional Overturning Circulation (AMOC) over the 30 000 years; a more sensitive AMOC would also be likely to lead to greater disequilibrium. We investigate the method of accelerating the boundary conditions of a transient simulation and find that the Southern Ocean is the region most affected by the acceleration. The Northern Hemisphere, even with a factor of 10 acceleration, is relatively unaffected. The results are robust to changes to several tunable parameters in the model. They also hold when a higher vertical resolution is used in the ocean. Article in Journal/Newspaper ice core Ice Sheet Sea ice Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 D. J. Lunt M. S. Williamson P. J. Valdes T. M. Lenton R. Marsh Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
We examine several aspects of the ocean-atmosphere system over the last 30 000 years, by carrying out simulations with prescribed ice sheets, atmospheric CO 2 concentration, and orbital parameters. We use the GENIE-1 model with a frictional geostrophic ocean, dynamic sea ice, an energy balance atmosphere, and a land-surface scheme with fixed vegetation. A transient simulation, with boundary conditions derived from ice-core records and ice sheet reconstructions, is compared with equilibrium snapshot simulations, including the Last Glacial Maximum (21 000 years before present; 21 kyrBP), mid-Holocene (6 kyrBP) and pre-industrial. The equilibrium snapshot simulations are all very similar to their corresponding time period in the transient simulation, indicating that over the last 30 000 years, the model's ocean-atmosphere system is close to equilibrium with its boundary conditions. However, our simulations neglect the transfer of fresh water from and to the ocean, resulting from the growth and decay of ice sheets, which would, in reality, lead to greater disequilibrium. Additionally, the GENIE-1 model exhibits a rather limited response in terms of its Atlantic Meridional Overturning Circulation (AMOC) over the 30 000 years; a more sensitive AMOC would also be likely to lead to greater disequilibrium. We investigate the method of accelerating the boundary conditions of a transient simulation and find that the Southern Ocean is the region most affected by the acceleration. The Northern Hemisphere, even with a factor of 10 acceleration, is relatively unaffected. The results are robust to changes to several tunable parameters in the model. They also hold when a higher vertical resolution is used in the ocean. |
format |
Article in Journal/Newspaper |
author |
D. J. Lunt M. S. Williamson P. J. Valdes T. M. Lenton R. Marsh |
author_facet |
D. J. Lunt M. S. Williamson P. J. Valdes T. M. Lenton R. Marsh |
author_sort |
D. J. Lunt |
title |
Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model |
title_short |
Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model |
title_full |
Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model |
title_fullStr |
Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model |
title_full_unstemmed |
Comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the GENIE-1 model |
title_sort |
comparing transient, accelerated, and equilibrium simulations of the last 30 000 years with the genie-1 model |
publisher |
Copernicus Publications |
publishDate |
2006 |
url |
https://doaj.org/article/e1d25875221f4b99a6f7af77c293cc69 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
ice core Ice Sheet Sea ice Southern Ocean |
genre_facet |
ice core Ice Sheet Sea ice Southern Ocean |
op_source |
Climate of the Past, Vol 2, Iss 2, Pp 221-235 (2006) |
op_relation |
http://www.clim-past.net/2/221/2006/cp-2-221-2006.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 https://doaj.org/article/e1d25875221f4b99a6f7af77c293cc69 |
_version_ |
1766029651014057984 |