Spatiotemporal dynamics of ice streams due to a triple-valued sliding law
We show that a triple-valued sliding law can be heuristically motivated by the transverse spatial structure of an ice-stream velocity field using a simple one-dimensional model. We then demonstrate that such a sliding law can lead to some interesting stream-like patterns and time-oscillatory solutio...
Published in: | Journal of Fluid Mechanics |
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Language: | English |
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Cambridge University Press (CUP)
2009
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Online Access: | http://dx.doi.org/10.1017/s0022112009991406 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112009991406 |
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crcambridgeupr:10.1017/s0022112009991406 2024-09-30T14:36:40+00:00 Spatiotemporal dynamics of ice streams due to a triple-valued sliding law SAYAG, ROIY TZIPERMAN, ELI 2009 http://dx.doi.org/10.1017/s0022112009991406 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112009991406 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Fluid Mechanics volume 640, page 483-505 ISSN 0022-1120 1469-7645 journal-article 2009 crcambridgeupr https://doi.org/10.1017/s0022112009991406 2024-09-04T04:03:43Z We show that a triple-valued sliding law can be heuristically motivated by the transverse spatial structure of an ice-stream velocity field using a simple one-dimensional model. We then demonstrate that such a sliding law can lead to some interesting stream-like patterns and time-oscillatory solutions. We find a generation of rapid stream-like solutions within a slow ice-sheet flow, separated by narrow internal boundary layers (shear margins), and analyse numerical simulations in two horizontal dimensions over a homogeneous bed and including longitudinal shear stresses. Different qualitative behaviours are obtained by changing a single physical parameter, a mass source magnitude, leading to changes from a slow creeping flow to a relaxation oscillation of the stream pattern, and to steady ice-stream-like solution. We show that the adjustment of the ice-flow shear margins to changes in the driving stress in the one-dimensional approximation is governed by a form of the Ginzburg–Landau equation and use stability analysis to understand this adjustment. In the model analysed here, the width scale of the stream is not set spontaneously by the ice flow dynamics, but rather, it is related to the mass source intensity and spatial distribution. Article in Journal/Newspaper Ice Sheet Cambridge University Press Journal of Fluid Mechanics 640 483 505 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
We show that a triple-valued sliding law can be heuristically motivated by the transverse spatial structure of an ice-stream velocity field using a simple one-dimensional model. We then demonstrate that such a sliding law can lead to some interesting stream-like patterns and time-oscillatory solutions. We find a generation of rapid stream-like solutions within a slow ice-sheet flow, separated by narrow internal boundary layers (shear margins), and analyse numerical simulations in two horizontal dimensions over a homogeneous bed and including longitudinal shear stresses. Different qualitative behaviours are obtained by changing a single physical parameter, a mass source magnitude, leading to changes from a slow creeping flow to a relaxation oscillation of the stream pattern, and to steady ice-stream-like solution. We show that the adjustment of the ice-flow shear margins to changes in the driving stress in the one-dimensional approximation is governed by a form of the Ginzburg–Landau equation and use stability analysis to understand this adjustment. In the model analysed here, the width scale of the stream is not set spontaneously by the ice flow dynamics, but rather, it is related to the mass source intensity and spatial distribution. |
format |
Article in Journal/Newspaper |
author |
SAYAG, ROIY TZIPERMAN, ELI |
spellingShingle |
SAYAG, ROIY TZIPERMAN, ELI Spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
author_facet |
SAYAG, ROIY TZIPERMAN, ELI |
author_sort |
SAYAG, ROIY |
title |
Spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
title_short |
Spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
title_full |
Spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
title_fullStr |
Spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
title_full_unstemmed |
Spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
title_sort |
spatiotemporal dynamics of ice streams due to a triple-valued sliding law |
publisher |
Cambridge University Press (CUP) |
publishDate |
2009 |
url |
http://dx.doi.org/10.1017/s0022112009991406 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112009991406 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Journal of Fluid Mechanics volume 640, page 483-505 ISSN 0022-1120 1469-7645 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0022112009991406 |
container_title |
Journal of Fluid Mechanics |
container_volume |
640 |
container_start_page |
483 |
op_container_end_page |
505 |
_version_ |
1811639679326355456 |