Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles
A two-dimensional model which links the atmosphere, the mixed layer of the ocean, the sea ice, the continents, the ice sheets and their underlying bedrock has been used to test the Milankovitch theory over the last two glacial-interglacial cycles. A series of sensitivity analyses have allowed us to...
Published in: | Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences |
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Online Access: | http://hdl.handle.net/2078.1/49540 https://doi.org/10.1098/rstb.1993.0110 |
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ftunistlouisbrus:oai:dial.uclouvain.be:boreal:49540 2024-05-12T08:05:14+00:00 Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles Berger, André Tricot, C. Gallee, H. Loutre, Marie-France UCL - SC/PHYS - Département de physique 1993 http://hdl.handle.net/2078.1/49540 https://doi.org/10.1098/rstb.1993.0110 eng eng Royal Soc London boreal:49540 http://hdl.handle.net/2078.1/49540 doi:10.1098/rstb.1993.0110 urn:ISSN:0962-8436 urn:EISSN:1471-2970 Royal Society of London. Philosophical Transactions. Biological Sciences, Vol. 341, no. 1297, p. 253-261 (1993) info:eu-repo/semantics/article 1993 ftunistlouisbrus https://doi.org/10.1098/rstb.1993.0110 2024-04-18T18:12:56Z A two-dimensional model which links the atmosphere, the mixed layer of the ocean, the sea ice, the continents, the ice sheets and their underlying bedrock has been used to test the Milankovitch theory over the last two glacial-interglacial cycles. A series of sensitivity analyses have allowed us to understand better the internal mechanisms which drive the simulated climate system and in particular the feedbacks related to surface albedo and water vapour. It was found that orbital variations alone can induce, in such a system, feedbacks sufficient to generate the low frequency part of the climatic variations over the last 122 ka. These simulated variations at the astronomical timescale are broadly in agreement with reconstructions of ice-sheet volume and of sea level independently obtained from geological data. Imperfections in the stimulated climate were the insufficient southward extent of the ice sheets and the too small hemispheric cooling at the last glacial maximum. These deficiencies were partly remedied in a further experiment by using the time-dependent atmospheric CO2 concentration given by the Vostok ice core in addition to the astronomical forcing. In this transient simulation, 70% of the Northern Hemisphere ice volume is related to the astronomical forcing and the related changes in the albedo, the remaining 30% being due to the CO2 changes. Analysis of the processes involved shows that variations of ablation are more important for the ice-sheet response than are variations of snow precipitation. A key mechanism in the deglaciation after the last glacial maximum appears to be the 'ageing' of snow which significantly decreases its albedo. The other factors which play an important role are ice-sheet altitude, insolation, taiga cover, ice-albedo feedback, ice-sheet configuration ('continentality' and 'desert' effect), isostatic rebound, CO2 changes and temperature-water vapour feedback. Numerical experiments have also been carried out with a one-dimensional radiative-convective model in order to ... Article in Journal/Newspaper ice core Ice Sheet Sea ice taiga DIAL@USL-B (Université Saint-Louis, Bruxelles) Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 341 1297 253 261 |
institution |
Open Polar |
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DIAL@USL-B (Université Saint-Louis, Bruxelles) |
op_collection_id |
ftunistlouisbrus |
language |
English |
description |
A two-dimensional model which links the atmosphere, the mixed layer of the ocean, the sea ice, the continents, the ice sheets and their underlying bedrock has been used to test the Milankovitch theory over the last two glacial-interglacial cycles. A series of sensitivity analyses have allowed us to understand better the internal mechanisms which drive the simulated climate system and in particular the feedbacks related to surface albedo and water vapour. It was found that orbital variations alone can induce, in such a system, feedbacks sufficient to generate the low frequency part of the climatic variations over the last 122 ka. These simulated variations at the astronomical timescale are broadly in agreement with reconstructions of ice-sheet volume and of sea level independently obtained from geological data. Imperfections in the stimulated climate were the insufficient southward extent of the ice sheets and the too small hemispheric cooling at the last glacial maximum. These deficiencies were partly remedied in a further experiment by using the time-dependent atmospheric CO2 concentration given by the Vostok ice core in addition to the astronomical forcing. In this transient simulation, 70% of the Northern Hemisphere ice volume is related to the astronomical forcing and the related changes in the albedo, the remaining 30% being due to the CO2 changes. Analysis of the processes involved shows that variations of ablation are more important for the ice-sheet response than are variations of snow precipitation. A key mechanism in the deglaciation after the last glacial maximum appears to be the 'ageing' of snow which significantly decreases its albedo. The other factors which play an important role are ice-sheet altitude, insolation, taiga cover, ice-albedo feedback, ice-sheet configuration ('continentality' and 'desert' effect), isostatic rebound, CO2 changes and temperature-water vapour feedback. Numerical experiments have also been carried out with a one-dimensional radiative-convective model in order to ... |
author2 |
UCL - SC/PHYS - Département de physique |
format |
Article in Journal/Newspaper |
author |
Berger, André Tricot, C. Gallee, H. Loutre, Marie-France |
spellingShingle |
Berger, André Tricot, C. Gallee, H. Loutre, Marie-France Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles |
author_facet |
Berger, André Tricot, C. Gallee, H. Loutre, Marie-France |
author_sort |
Berger, André |
title |
Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles |
title_short |
Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles |
title_full |
Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles |
title_fullStr |
Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles |
title_full_unstemmed |
Water-vapor, Co2 and Insolation Over the Last Glacial Interglacial Cycles |
title_sort |
water-vapor, co2 and insolation over the last glacial interglacial cycles |
publisher |
Royal Soc London |
publishDate |
1993 |
url |
http://hdl.handle.net/2078.1/49540 https://doi.org/10.1098/rstb.1993.0110 |
genre |
ice core Ice Sheet Sea ice taiga |
genre_facet |
ice core Ice Sheet Sea ice taiga |
op_source |
Royal Society of London. Philosophical Transactions. Biological Sciences, Vol. 341, no. 1297, p. 253-261 (1993) |
op_relation |
boreal:49540 http://hdl.handle.net/2078.1/49540 doi:10.1098/rstb.1993.0110 urn:ISSN:0962-8436 urn:EISSN:1471-2970 |
op_doi |
https://doi.org/10.1098/rstb.1993.0110 |
container_title |
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences |
container_volume |
341 |
container_issue |
1297 |
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253 |
op_container_end_page |
261 |
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