Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing
Major uncertainties in the response of ice sheets to environmental forcing are due to subglacial processes. These processes pertain to the type of sliding or friction law as well as the spatial and temporal evolution of the effective pressure at the base of ice sheets. We evaluate the classic Weertm...
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Online Access: | https://nrl.northumbria.ac.uk/id/eprint/50500/ https://doi.org/10.5194/tc-16-4537-2022 https://nrl.northumbria.ac.uk/id/eprint/50500/1/tc-16-4537-2022.pdf |
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:50500 2023-05-15T13:53:41+02:00 Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing Kazmierczak, Elise Sun, Sainan Coulon, Violaine Pattyn, Frank 2022-10-27 text https://nrl.northumbria.ac.uk/id/eprint/50500/ https://doi.org/10.5194/tc-16-4537-2022 https://nrl.northumbria.ac.uk/id/eprint/50500/1/tc-16-4537-2022.pdf en eng Coperincus https://nrl.northumbria.ac.uk/id/eprint/50500/1/tc-16-4537-2022.pdf Kazmierczak, Elise, Sun, Sainan, Coulon, Violaine and Pattyn, Frank (2022) Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing. The Cryosphere, 16 (10). pp. 4537-4552. ISSN 1994-0424 cc_by_4_0 CC-BY F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2022 ftunivnorthumb https://doi.org/10.5194/tc-16-4537-2022 2022-11-03T23:31:00Z Major uncertainties in the response of ice sheets to environmental forcing are due to subglacial processes. These processes pertain to the type of sliding or friction law as well as the spatial and temporal evolution of the effective pressure at the base of ice sheets. We evaluate the classic Weertman–Budd sliding law for different power exponents (viscous to near plastic) and for different representations of effective pressure at the base of the ice sheet, commonly used for hard and soft beds. The sensitivity of the above slip laws is evaluated for the Antarctic ice sheet in two types of experiments: (i) the ABUMIP experiments in which ice shelves are instantaneously removed, leading to rapid grounding-line retreat and ice sheet collapse, and (ii) the ISMIP6 experiments with realistic ocean and atmosphere forcings for different Representative Concentration Pathway (RCP) scenarios. Results confirm earlier work that the power in the sliding law is the most determining factor in the sensitivity of the ice sheet to climatic forcing, where a higher power in the sliding law leads to increased mass loss for a given forcing. Here we show that spatial and temporal changes in water pressure or water flux at the base modulate basal sliding for a given power, especially for high-end scenarios, such as ABUMIP. In particular, subglacial models depending on subglacial water pressure decrease effective pressure significantly near the grounding line, leading to an increased sensitivity to climatic forcing for a given power in the sliding law. This dependency is, however, less clear under realistic forcing scenarios (ISMIP6). Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelves The Cryosphere Northumbria University, Newcastle: Northumbria Research Link (NRL) Antarctic The Antarctic Weertman ENVELOPE(-67.753,-67.753,-66.972,-66.972) The Cryosphere 16 10 4537 4552 |
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 Kazmierczak, Elise Sun, Sainan Coulon, Violaine Pattyn, Frank Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
topic_facet |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
Major uncertainties in the response of ice sheets to environmental forcing are due to subglacial processes. These processes pertain to the type of sliding or friction law as well as the spatial and temporal evolution of the effective pressure at the base of ice sheets. We evaluate the classic Weertman–Budd sliding law for different power exponents (viscous to near plastic) and for different representations of effective pressure at the base of the ice sheet, commonly used for hard and soft beds. The sensitivity of the above slip laws is evaluated for the Antarctic ice sheet in two types of experiments: (i) the ABUMIP experiments in which ice shelves are instantaneously removed, leading to rapid grounding-line retreat and ice sheet collapse, and (ii) the ISMIP6 experiments with realistic ocean and atmosphere forcings for different Representative Concentration Pathway (RCP) scenarios. Results confirm earlier work that the power in the sliding law is the most determining factor in the sensitivity of the ice sheet to climatic forcing, where a higher power in the sliding law leads to increased mass loss for a given forcing. Here we show that spatial and temporal changes in water pressure or water flux at the base modulate basal sliding for a given power, especially for high-end scenarios, such as ABUMIP. In particular, subglacial models depending on subglacial water pressure decrease effective pressure significantly near the grounding line, leading to an increased sensitivity to climatic forcing for a given power in the sliding law. This dependency is, however, less clear under realistic forcing scenarios (ISMIP6). |
format |
Article in Journal/Newspaper |
author |
Kazmierczak, Elise Sun, Sainan Coulon, Violaine Pattyn, Frank |
author_facet |
Kazmierczak, Elise Sun, Sainan Coulon, Violaine Pattyn, Frank |
author_sort |
Kazmierczak, Elise |
title |
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
title_short |
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
title_full |
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
title_fullStr |
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
title_full_unstemmed |
Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
title_sort |
subglacial hydrology modulates basal sliding response of the antarctic ice sheet to climate forcing |
publisher |
Coperincus |
publishDate |
2022 |
url |
https://nrl.northumbria.ac.uk/id/eprint/50500/ https://doi.org/10.5194/tc-16-4537-2022 https://nrl.northumbria.ac.uk/id/eprint/50500/1/tc-16-4537-2022.pdf |
long_lat |
ENVELOPE(-67.753,-67.753,-66.972,-66.972) |
geographic |
Antarctic The Antarctic Weertman |
geographic_facet |
Antarctic The Antarctic Weertman |
genre |
Antarc* Antarctic Ice Sheet Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelves The Cryosphere |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/50500/1/tc-16-4537-2022.pdf Kazmierczak, Elise, Sun, Sainan, Coulon, Violaine and Pattyn, Frank (2022) Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing. The Cryosphere, 16 (10). pp. 4537-4552. ISSN 1994-0424 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-16-4537-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
10 |
container_start_page |
4537 |
op_container_end_page |
4552 |
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1766259065415008256 |