Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet
We use a three-dimensional thermo-mechanically coupled model of the Greenland ice sheet to assess the effects of marginal perturbations on volume changes on centennial timescales. The model is designed to allow for five ice dynamic formulations using different approximations to the force balance. Th...
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Online Access: | https://doi.org/10.5194/tc-7-183-2013 http://www.the-cryosphere.net/7/183/2013/tc-7-183-2013.pdf https://doaj.org/article/6496cabd0d5f4faeaa362f2bc8b9c267 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:6496cabd0d5f4faeaa362f2bc8b9c267 2023-05-15T16:28:40+02:00 Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet J. J. Fürst H. Goelzer P. Huybrechts 2013-02-01 https://doi.org/10.5194/tc-7-183-2013 http://www.the-cryosphere.net/7/183/2013/tc-7-183-2013.pdf https://doaj.org/article/6496cabd0d5f4faeaa362f2bc8b9c267 en eng Copernicus Publications doi:10.5194/tc-7-183-2013 1994-0416 1994-0424 http://www.the-cryosphere.net/7/183/2013/tc-7-183-2013.pdf https://doaj.org/article/6496cabd0d5f4faeaa362f2bc8b9c267 undefined The Cryosphere, Vol 7, Iss 1, Pp 183-199 (2013) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2013 fttriple https://doi.org/10.5194/tc-7-183-2013 2023-01-22T18:59:33Z We use a three-dimensional thermo-mechanically coupled model of the Greenland ice sheet to assess the effects of marginal perturbations on volume changes on centennial timescales. The model is designed to allow for five ice dynamic formulations using different approximations to the force balance. The standard model is based on the shallow ice approximation for both ice deformation and basal sliding. A second model version relies on a higher-order Blatter/Pattyn type of core that resolves effects from gradients in longitudinal stresses and transverse horizontal shearing, i.e. membrane-like stresses. Together with three intermediate model versions, these five versions allow for gradually more dynamic feedbacks from membrane stresses. Idealised experiments are conducted on various resolutions to compare the time-dependent response to imposed accelerations at the marine ice front. If such marginal accelerations are to have an appreciable effect on total mass loss on a century timescale, a fast mechanism to transmit such perturbations inland is required. While the forcing is independent of the model version, inclusion of direct horizontal coupling allows the initial speed-up to reach several tens of kilometres inland. Within one century, effects from gradients in membrane stress alter the inland signal propagation and transmit additional dynamic thinning to the ice sheet interior. But the centennial overall volume loss differs only by some percents from the standard model, as the dominant response is a diffusive inland propagation of geometric changes. For the experiments considered, this volume response is even attenuated by direct horizontal coupling. The reason is a faster adjustment of the sliding regime by instant stress transmission in models that account for the effect of membrane stresses. Ultimately, horizontal coupling decreases the reaction time to perturbations at the ice sheet margin. These findings suggest that for modelling the mass evolution of a large-scale ice sheet, effects from diffusive geometric ... Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere Unknown Greenland The Cryosphere 7 1 183 199 |
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English |
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geo envir J. J. Fürst H. Goelzer P. Huybrechts Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet |
topic_facet |
geo envir |
description |
We use a three-dimensional thermo-mechanically coupled model of the Greenland ice sheet to assess the effects of marginal perturbations on volume changes on centennial timescales. The model is designed to allow for five ice dynamic formulations using different approximations to the force balance. The standard model is based on the shallow ice approximation for both ice deformation and basal sliding. A second model version relies on a higher-order Blatter/Pattyn type of core that resolves effects from gradients in longitudinal stresses and transverse horizontal shearing, i.e. membrane-like stresses. Together with three intermediate model versions, these five versions allow for gradually more dynamic feedbacks from membrane stresses. Idealised experiments are conducted on various resolutions to compare the time-dependent response to imposed accelerations at the marine ice front. If such marginal accelerations are to have an appreciable effect on total mass loss on a century timescale, a fast mechanism to transmit such perturbations inland is required. While the forcing is independent of the model version, inclusion of direct horizontal coupling allows the initial speed-up to reach several tens of kilometres inland. Within one century, effects from gradients in membrane stress alter the inland signal propagation and transmit additional dynamic thinning to the ice sheet interior. But the centennial overall volume loss differs only by some percents from the standard model, as the dominant response is a diffusive inland propagation of geometric changes. For the experiments considered, this volume response is even attenuated by direct horizontal coupling. The reason is a faster adjustment of the sliding regime by instant stress transmission in models that account for the effect of membrane stresses. Ultimately, horizontal coupling decreases the reaction time to perturbations at the ice sheet margin. These findings suggest that for modelling the mass evolution of a large-scale ice sheet, effects from diffusive geometric ... |
format |
Article in Journal/Newspaper |
author |
J. J. Fürst H. Goelzer P. Huybrechts |
author_facet |
J. J. Fürst H. Goelzer P. Huybrechts |
author_sort |
J. J. Fürst |
title |
Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet |
title_short |
Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet |
title_full |
Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet |
title_fullStr |
Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet |
title_full_unstemmed |
Effect of higher-order stress gradients on the centennial mass evolution of the Greenland ice sheet |
title_sort |
effect of higher-order stress gradients on the centennial mass evolution of the greenland ice sheet |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/tc-7-183-2013 http://www.the-cryosphere.net/7/183/2013/tc-7-183-2013.pdf https://doaj.org/article/6496cabd0d5f4faeaa362f2bc8b9c267 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 7, Iss 1, Pp 183-199 (2013) |
op_relation |
doi:10.5194/tc-7-183-2013 1994-0416 1994-0424 http://www.the-cryosphere.net/7/183/2013/tc-7-183-2013.pdf https://doaj.org/article/6496cabd0d5f4faeaa362f2bc8b9c267 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-7-183-2013 |
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The Cryosphere |
container_volume |
7 |
container_issue |
1 |
container_start_page |
183 |
op_container_end_page |
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