Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system
We study the mechanisms of glacial inception by using the Earth system model of intermediate complexity, CLIMBER-2, which encompasses dynamic modules of the atmosphere, ocean, biosphere and ice sheets. Ice-sheet dynamics are described by the three-dimensional polythermal ice-sheet model SICOPOLIS. W...
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ftpubman:oai:pure.mpg.de:item_995021 2023-08-27T04:10:01+02:00 Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system Calov, R. Ganopolski, A. Claussen, M. Petoukhov, V. Greve, R. 2005 application/pdf http://hdl.handle.net/11858/00-001M-0000-0011-FF98-5 http://hdl.handle.net/11858/00-001M-0000-0011-FF97-7 eng eng info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-005-0007-6 http://hdl.handle.net/11858/00-001M-0000-0011-FF98-5 http://hdl.handle.net/11858/00-001M-0000-0011-FF97-7 Climate Dynamics info:eu-repo/semantics/article 2005 ftpubman https://doi.org/10.1007/s00382-005-0007-6 2023-08-02T01:34:53Z We study the mechanisms of glacial inception by using the Earth system model of intermediate complexity, CLIMBER-2, which encompasses dynamic modules of the atmosphere, ocean, biosphere and ice sheets. Ice-sheet dynamics are described by the three-dimensional polythermal ice-sheet model SICOPOLIS. We have performed transient experiments starting at the Eemiam interglacial, at 126 ky BP (126,000 years before present). The model runs for 26 kyr with time-dependent orbital and CO2 forcings. The model simulates a rapid expansion of the area covered by inland ice in the Northern Hemisphere, predominantly over Northern America, starting at about 117 kyr BP. During the next 7 kyr, the ice volume grows gradually in the model at a rate which corresponds to a change in sea level of 10 m per millennium. We have shown that the simulated glacial inception represents a bifurcation transition in the climate system from an interglacial to a glacial state caused by the strong snow-albedo feedback. This transition occurs when summer insolation at high latitudes of the Northern Hemisphere drops below a threshold value, which is only slightly lower than modern summer insolation. By performing long-term equilibrium runs, we find that for the present-day orbital parameters at least two different equilibrium states of the climate system exist—the glacial and the interglacial; however, for the low summer insolation corresponding to 115 kyr BP, we find only one, glacial, equilibrium state, while for the high summer insolation corresponding to 126 kyr BP only an interglacial state exists in the model Article in Journal/Newspaper Ice Sheet Max Planck Society: MPG.PuRe Climate Dynamics 24 6 545 561 |
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Open Polar |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
We study the mechanisms of glacial inception by using the Earth system model of intermediate complexity, CLIMBER-2, which encompasses dynamic modules of the atmosphere, ocean, biosphere and ice sheets. Ice-sheet dynamics are described by the three-dimensional polythermal ice-sheet model SICOPOLIS. We have performed transient experiments starting at the Eemiam interglacial, at 126 ky BP (126,000 years before present). The model runs for 26 kyr with time-dependent orbital and CO2 forcings. The model simulates a rapid expansion of the area covered by inland ice in the Northern Hemisphere, predominantly over Northern America, starting at about 117 kyr BP. During the next 7 kyr, the ice volume grows gradually in the model at a rate which corresponds to a change in sea level of 10 m per millennium. We have shown that the simulated glacial inception represents a bifurcation transition in the climate system from an interglacial to a glacial state caused by the strong snow-albedo feedback. This transition occurs when summer insolation at high latitudes of the Northern Hemisphere drops below a threshold value, which is only slightly lower than modern summer insolation. By performing long-term equilibrium runs, we find that for the present-day orbital parameters at least two different equilibrium states of the climate system exist—the glacial and the interglacial; however, for the low summer insolation corresponding to 115 kyr BP, we find only one, glacial, equilibrium state, while for the high summer insolation corresponding to 126 kyr BP only an interglacial state exists in the model |
format |
Article in Journal/Newspaper |
author |
Calov, R. Ganopolski, A. Claussen, M. Petoukhov, V. Greve, R. |
spellingShingle |
Calov, R. Ganopolski, A. Claussen, M. Petoukhov, V. Greve, R. Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system |
author_facet |
Calov, R. Ganopolski, A. Claussen, M. Petoukhov, V. Greve, R. |
author_sort |
Calov, R. |
title |
Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system |
title_short |
Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system |
title_full |
Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system |
title_fullStr |
Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system |
title_full_unstemmed |
Transient simulation of the last glacial inception. Part I: Glacial inception as a bifurcation in the climate system |
title_sort |
transient simulation of the last glacial inception. part i: glacial inception as a bifurcation in the climate system |
publishDate |
2005 |
url |
http://hdl.handle.net/11858/00-001M-0000-0011-FF98-5 http://hdl.handle.net/11858/00-001M-0000-0011-FF97-7 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Climate Dynamics |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-005-0007-6 http://hdl.handle.net/11858/00-001M-0000-0011-FF98-5 http://hdl.handle.net/11858/00-001M-0000-0011-FF97-7 |
op_doi |
https://doi.org/10.1007/s00382-005-0007-6 |
container_title |
Climate Dynamics |
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24 |
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6 |
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545 |
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561 |
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1775351756456198144 |