Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica
Given high-resolution satellite-derived surface elevation and velocity data, ice-sheet models generally estimate mechanical basal boundary conditions using surface-to-bed inversion methods. In this work, we address the sensitivity of results from inversion methods to the accuracy of the bed elevatio...
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Online Access: | https://nrl.northumbria.ac.uk/id/eprint/34427/ https://doi.org/10.3389/feart.2018.00033 https://nrl.northumbria.ac.uk/id/eprint/34427/1/Kyrke-Smith%20et%20al%20-%20Relevance%20of%20Detail%20in%20Basal%20Topography%20for%20Basal%20Slipperiness%20Inversions%20OA.pdf |
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:34427 2023-05-15T13:56:54+02:00 Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica Kyrke-Smith, Teresa Gudmundsson, Hilmar Farrell, Patrick 2018-04-11 text https://nrl.northumbria.ac.uk/id/eprint/34427/ https://doi.org/10.3389/feart.2018.00033 https://nrl.northumbria.ac.uk/id/eprint/34427/1/Kyrke-Smith%20et%20al%20-%20Relevance%20of%20Detail%20in%20Basal%20Topography%20for%20Basal%20Slipperiness%20Inversions%20OA.pdf en eng Frontiers https://nrl.northumbria.ac.uk/id/eprint/34427/1/Kyrke-Smith%20et%20al%20-%20Relevance%20of%20Detail%20in%20Basal%20Topography%20for%20Basal%20Slipperiness%20Inversions%20OA.pdf Kyrke-Smith, Teresa, Gudmundsson, Hilmar and Farrell, Patrick (2018) Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica. Frontiers in Earth Science, 6. ISSN 2296-6463 cc_by_4_0 CC-BY F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2018 ftunivnorthumb https://doi.org/10.3389/feart.2018.00033 2022-09-25T06:07:21Z Given high-resolution satellite-derived surface elevation and velocity data, ice-sheet models generally estimate mechanical basal boundary conditions using surface-to-bed inversion methods. In this work, we address the sensitivity of results from inversion methods to the accuracy of the bed elevation data on Pine Island Glacier. We show that misfit between observations and model output is reduced when high-resolution bed topography is used in the inverse model. By looking at results with a range of detail included in the bed elevation, we consider the separation of basal drag due to the bed topography (form drag) and that due to inherent bed properties (skin drag). The mean value of inverted basal shear stress, i.e., skin drag, is reduced when more detailed topography is included in the model. This suggests that without a fully resolved bed a significant amount of the basal shear stress recovered from inversion methods may be due to the unresolved bed topography. However, the spatial structure of the retrieved fields is robust as the bed accuracy is varied; the fields are instead sensitive to the degree of regularization applied to the inversion. While the implications for the future temporal evolution of PIG are not quantified here directly, our work raises the possibility that skin drag may be overestimated in the current generation of numerical ice-sheet models of this area. These shortcomings could be overcome by inverting simultaneously for both bed topography and basal slipperiness. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Pine Island Pine Island Glacier Northumbria University, Newcastle: Northumbria Research Link (NRL) Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Frontiers in Earth Science 6 |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F800 Physical and Terrestrial Geographical and Environmental Sciences Kyrke-Smith, Teresa Gudmundsson, Hilmar Farrell, Patrick Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica |
topic_facet |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
Given high-resolution satellite-derived surface elevation and velocity data, ice-sheet models generally estimate mechanical basal boundary conditions using surface-to-bed inversion methods. In this work, we address the sensitivity of results from inversion methods to the accuracy of the bed elevation data on Pine Island Glacier. We show that misfit between observations and model output is reduced when high-resolution bed topography is used in the inverse model. By looking at results with a range of detail included in the bed elevation, we consider the separation of basal drag due to the bed topography (form drag) and that due to inherent bed properties (skin drag). The mean value of inverted basal shear stress, i.e., skin drag, is reduced when more detailed topography is included in the model. This suggests that without a fully resolved bed a significant amount of the basal shear stress recovered from inversion methods may be due to the unresolved bed topography. However, the spatial structure of the retrieved fields is robust as the bed accuracy is varied; the fields are instead sensitive to the degree of regularization applied to the inversion. While the implications for the future temporal evolution of PIG are not quantified here directly, our work raises the possibility that skin drag may be overestimated in the current generation of numerical ice-sheet models of this area. These shortcomings could be overcome by inverting simultaneously for both bed topography and basal slipperiness. |
format |
Article in Journal/Newspaper |
author |
Kyrke-Smith, Teresa Gudmundsson, Hilmar Farrell, Patrick |
author_facet |
Kyrke-Smith, Teresa Gudmundsson, Hilmar Farrell, Patrick |
author_sort |
Kyrke-Smith, Teresa |
title |
Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica |
title_short |
Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica |
title_full |
Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica |
title_fullStr |
Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica |
title_full_unstemmed |
Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica |
title_sort |
relevance of detail in basal topography for basal slipperiness inversions: a case study on pine island glacier, antarctica |
publisher |
Frontiers |
publishDate |
2018 |
url |
https://nrl.northumbria.ac.uk/id/eprint/34427/ https://doi.org/10.3389/feart.2018.00033 https://nrl.northumbria.ac.uk/id/eprint/34427/1/Kyrke-Smith%20et%20al%20-%20Relevance%20of%20Detail%20in%20Basal%20Topography%20for%20Basal%20Slipperiness%20Inversions%20OA.pdf |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
Pine Island Glacier |
geographic_facet |
Pine Island Glacier |
genre |
Antarc* Antarctica Ice Sheet Pine Island Pine Island Glacier |
genre_facet |
Antarc* Antarctica Ice Sheet Pine Island Pine Island Glacier |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/34427/1/Kyrke-Smith%20et%20al%20-%20Relevance%20of%20Detail%20in%20Basal%20Topography%20for%20Basal%20Slipperiness%20Inversions%20OA.pdf Kyrke-Smith, Teresa, Gudmundsson, Hilmar and Farrell, Patrick (2018) Relevance of Detail in Basal Topography for Basal Slipperiness Inversions: A Case Study on Pine Island Glacier, Antarctica. Frontiers in Earth Science, 6. ISSN 2296-6463 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3389/feart.2018.00033 |
container_title |
Frontiers in Earth Science |
container_volume |
6 |
_version_ |
1766264491378475008 |