Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations
A two-dimensional climate model which links the northern hemisphere atmosphere, ocean mixed layer, sea ice, and continents has been asynchronously coupled to a model of the three main northern ice sheets and their underlying bedrock. The coupled model has been used to test the influence of several f...
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1992
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ftunivlouvain:oai:dial.uclouvain.be:boreal:50190 2024-05-12T08:05:14+00:00 Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations Gallee, H. van Ypersele de Strihou, Jean-Pascal Fichefet, Thierry Marsiat, I. Tricot, C. Berger, André UCL - SC/PHYS - Département de physique UCL - SST/ELI/ELIC - Earth & Climate 1992 http://hdl.handle.net/2078.1/50190 eng eng Amer Geophysical Union boreal:50190 http://hdl.handle.net/2078.1/50190 urn:ISSN:0148-0227 Journal of Geophysical Research, Vol. 97, no. D14, p. 15713-15740 (1992) info:eu-repo/semantics/article 1992 ftunivlouvain 2024-04-17T17:30:22Z A two-dimensional climate model which links the northern hemisphere atmosphere, ocean mixed layer, sea ice, and continents has been asynchronously coupled to a model of the three main northern ice sheets and their underlying bedrock. The coupled model has been used to test the influence of several factors, including snow surface albedo over the ice sheets, in producing plausible ice age simulations using astronomically derived insolation and CO2 data from the Vostok ice core. The impact of potentially important processes, such as the water vapor transport, clouds, and deep sea circulation, was not investigated in this study. After several sensitivity experiments designed to identify the main mechanism governing surface temperature and ice accumulation, the model is first run with ice sheet feedback by forcing it only with the astronomical insolation over the past 122 kyr. Large variations of ice volume are simulated between 122 and 55 kyr B.P., with a rapid latitudinal extension of the North American and Eurasian ice sheets starting at 120 kyr B.P. The simulated last glacial maximum is at 19 kyr B.P. The model is able to simulate deglaciation as well. The simulated evolution of the three northern ice sheets is generally in phase with geological reconstructions. The major discrepancy between the simulation and paleoclimate reconstructions lies in the underestimation of temperature variations (linked with an underestimation of the ice sheet extent and an excess in the prescribed CO2 concentration). Sensitivity experiments show that ablation is more important to the ice sheet response than snow precipitation variations. In the model a key mechanism in the deglaciation after the last glacial maximum appears to be the "aging" of snow, which decreases its albedo. The other factors which play an important role are, in decreasing level of importance, the ice sheet altitude, insolation, taiga cover, and ice sheet extent. A final set of experiments addresses the effects of CO2 on the simulated climate of the last glacial ... Article in Journal/Newspaper ice core Ice Sheet Sea ice taiga DIAL@UCLouvain (Université catholique de Louvain) |
institution |
Open Polar |
collection |
DIAL@UCLouvain (Université catholique de Louvain) |
op_collection_id |
ftunivlouvain |
language |
English |
description |
A two-dimensional climate model which links the northern hemisphere atmosphere, ocean mixed layer, sea ice, and continents has been asynchronously coupled to a model of the three main northern ice sheets and their underlying bedrock. The coupled model has been used to test the influence of several factors, including snow surface albedo over the ice sheets, in producing plausible ice age simulations using astronomically derived insolation and CO2 data from the Vostok ice core. The impact of potentially important processes, such as the water vapor transport, clouds, and deep sea circulation, was not investigated in this study. After several sensitivity experiments designed to identify the main mechanism governing surface temperature and ice accumulation, the model is first run with ice sheet feedback by forcing it only with the astronomical insolation over the past 122 kyr. Large variations of ice volume are simulated between 122 and 55 kyr B.P., with a rapid latitudinal extension of the North American and Eurasian ice sheets starting at 120 kyr B.P. The simulated last glacial maximum is at 19 kyr B.P. The model is able to simulate deglaciation as well. The simulated evolution of the three northern ice sheets is generally in phase with geological reconstructions. The major discrepancy between the simulation and paleoclimate reconstructions lies in the underestimation of temperature variations (linked with an underestimation of the ice sheet extent and an excess in the prescribed CO2 concentration). Sensitivity experiments show that ablation is more important to the ice sheet response than snow precipitation variations. In the model a key mechanism in the deglaciation after the last glacial maximum appears to be the "aging" of snow, which decreases its albedo. The other factors which play an important role are, in decreasing level of importance, the ice sheet altitude, insolation, taiga cover, and ice sheet extent. A final set of experiments addresses the effects of CO2 on the simulated climate of the last glacial ... |
author2 |
UCL - SC/PHYS - Département de physique UCL - SST/ELI/ELIC - Earth & Climate |
format |
Article in Journal/Newspaper |
author |
Gallee, H. van Ypersele de Strihou, Jean-Pascal Fichefet, Thierry Marsiat, I. Tricot, C. Berger, André |
spellingShingle |
Gallee, H. van Ypersele de Strihou, Jean-Pascal Fichefet, Thierry Marsiat, I. Tricot, C. Berger, André Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations |
author_facet |
Gallee, H. van Ypersele de Strihou, Jean-Pascal Fichefet, Thierry Marsiat, I. Tricot, C. Berger, André |
author_sort |
Gallee, H. |
title |
Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations |
title_short |
Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations |
title_full |
Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations |
title_fullStr |
Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations |
title_full_unstemmed |
Simulation of the Last Glacial Cycle By a Coupled, Sectorially Averaged Climate-ice Sheet Model .2. Response To Insolation and Co2 Variations |
title_sort |
simulation of the last glacial cycle by a coupled, sectorially averaged climate-ice sheet model .2. response to insolation and co2 variations |
publisher |
Amer Geophysical Union |
publishDate |
1992 |
url |
http://hdl.handle.net/2078.1/50190 |
genre |
ice core Ice Sheet Sea ice taiga |
genre_facet |
ice core Ice Sheet Sea ice taiga |
op_source |
Journal of Geophysical Research, Vol. 97, no. D14, p. 15713-15740 (1992) |
op_relation |
boreal:50190 http://hdl.handle.net/2078.1/50190 urn:ISSN:0148-0227 |
_version_ |
1798847502072414208 |