A quasi-analytical ice-sheet model for climate studies
A simple quasi-analytical model is developed to study the response of ice-sheets to climate change. The model is axisymmetrical and rests on a bed with a constant slope. The mechanics are highly parameterised. The climatic conditions are represented by the altitude of the runoff line. Above the runo...
Published in: | Nonlinear Processes in Geophysics |
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Language: | English |
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Copernicus Publications
2003
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00035203 2023-05-15T16:13:09+02:00 A quasi-analytical ice-sheet model for climate studies Oerlemans, J. 2003-10 electronic https://doi.org/10.5194/npg-10-441-2003 https://noa.gwlb.de/receive/cop_mods_00035203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035157/npg-10-441-2003.pdf https://npg.copernicus.org/articles/10/441/2003/npg-10-441-2003.pdf eng eng Copernicus Publications Nonlinear Processes in Geophysics -- http://www.bibliothek.uni-regensburg.de/ezeit/?2078085 -- http://www.nonlin-processes-geophys.net/ -- http://www.copernicus.org/EGU/npg/npg.htm -- 1607-7946 https://doi.org/10.5194/npg-10-441-2003 https://noa.gwlb.de/receive/cop_mods_00035203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035157/npg-10-441-2003.pdf https://npg.copernicus.org/articles/10/441/2003/npg-10-441-2003.pdf https://open-access.net/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2003 ftnonlinearchiv https://doi.org/10.5194/npg-10-441-2003 2022-02-08T22:44:50Z A simple quasi-analytical model is developed to study the response of ice-sheets to climate change. The model is axisymmetrical and rests on a bed with a constant slope. The mechanics are highly parameterised. The climatic conditions are represented by the altitude of the runoff line. Above the runoff line the accumulation rate is constant (but may depend on, for instance, the ice-sheet size), below the runoff line the balance gradient is constant. The ice-sheet may extend into the sea and can respond to changes in sea level. At the grounding line the ice velocity is assumed to be proportional to the water depth. For this set-up an explicit expression for the total mass budget of the ice-sheet is derived. To illustrate the properties and possibilities of the model, equilibrium states are analysed and the response to periodic forcing is studied as well. The coupling of mass balance and surface elevation of the ice-sheet leads to nonlinear behaviour and branching of the equilibrium solutions. The qualitative behaviour of the system is that of the cusp catastrophe. Nonlinear effects are more pronounced when the slope of the bed is smaller. A case is discussed in which two ice-sheets are coupled by making the altitude of the runoff line dependent on the total area of the two ice-sheets. On two continents, having a slightly different glaciation threshold, periodic forcing of the altitude of the runoff line is imposed. It is shown that in such a situation variations on a long time scale (two to three times the period of the forcing) are introduced. Finally the model is forced by the GISP d18O record for the last 120 000 years. For an appropriate choice of parameters the model simulates well the waxing and waning of the Laurentide, Fennoscandian and Barentsz ice-sheets. Article in Journal/Newspaper Fennoscandian Ice Sheet Niedersächsisches Online-Archiv NOA Nonlinear Processes in Geophysics 10 4/5 441 452 |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Oerlemans, J. A quasi-analytical ice-sheet model for climate studies |
topic_facet |
article Verlagsveröffentlichung |
description |
A simple quasi-analytical model is developed to study the response of ice-sheets to climate change. The model is axisymmetrical and rests on a bed with a constant slope. The mechanics are highly parameterised. The climatic conditions are represented by the altitude of the runoff line. Above the runoff line the accumulation rate is constant (but may depend on, for instance, the ice-sheet size), below the runoff line the balance gradient is constant. The ice-sheet may extend into the sea and can respond to changes in sea level. At the grounding line the ice velocity is assumed to be proportional to the water depth. For this set-up an explicit expression for the total mass budget of the ice-sheet is derived. To illustrate the properties and possibilities of the model, equilibrium states are analysed and the response to periodic forcing is studied as well. The coupling of mass balance and surface elevation of the ice-sheet leads to nonlinear behaviour and branching of the equilibrium solutions. The qualitative behaviour of the system is that of the cusp catastrophe. Nonlinear effects are more pronounced when the slope of the bed is smaller. A case is discussed in which two ice-sheets are coupled by making the altitude of the runoff line dependent on the total area of the two ice-sheets. On two continents, having a slightly different glaciation threshold, periodic forcing of the altitude of the runoff line is imposed. It is shown that in such a situation variations on a long time scale (two to three times the period of the forcing) are introduced. Finally the model is forced by the GISP d18O record for the last 120 000 years. For an appropriate choice of parameters the model simulates well the waxing and waning of the Laurentide, Fennoscandian and Barentsz ice-sheets. |
format |
Article in Journal/Newspaper |
author |
Oerlemans, J. |
author_facet |
Oerlemans, J. |
author_sort |
Oerlemans, J. |
title |
A quasi-analytical ice-sheet model for climate studies |
title_short |
A quasi-analytical ice-sheet model for climate studies |
title_full |
A quasi-analytical ice-sheet model for climate studies |
title_fullStr |
A quasi-analytical ice-sheet model for climate studies |
title_full_unstemmed |
A quasi-analytical ice-sheet model for climate studies |
title_sort |
quasi-analytical ice-sheet model for climate studies |
publisher |
Copernicus Publications |
publishDate |
2003 |
url |
https://doi.org/10.5194/npg-10-441-2003 https://noa.gwlb.de/receive/cop_mods_00035203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035157/npg-10-441-2003.pdf https://npg.copernicus.org/articles/10/441/2003/npg-10-441-2003.pdf |
genre |
Fennoscandian Ice Sheet |
genre_facet |
Fennoscandian Ice Sheet |
op_relation |
Nonlinear Processes in Geophysics -- http://www.bibliothek.uni-regensburg.de/ezeit/?2078085 -- http://www.nonlin-processes-geophys.net/ -- http://www.copernicus.org/EGU/npg/npg.htm -- 1607-7946 https://doi.org/10.5194/npg-10-441-2003 https://noa.gwlb.de/receive/cop_mods_00035203 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035157/npg-10-441-2003.pdf https://npg.copernicus.org/articles/10/441/2003/npg-10-441-2003.pdf |
op_rights |
https://open-access.net/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/npg-10-441-2003 |
container_title |
Nonlinear Processes in Geophysics |
container_volume |
10 |
container_issue |
4/5 |
container_start_page |
441 |
op_container_end_page |
452 |
_version_ |
1765998760744189952 |