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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ftdoajarticles:oai:doaj.org/article:1bb185d3c88a4591bac04951ce34564c 2023-05-15T14:04:26+02:00 Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing E. Kazmierczak S. Sun V. Coulon F. Pattyn 2022-10-01T00:00:00Z https://doi.org/10.5194/tc-16-4537-2022 https://doaj.org/article/1bb185d3c88a4591bac04951ce34564c EN eng Copernicus Publications https://tc.copernicus.org/articles/16/4537/2022/tc-16-4537-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4537-2022 1994-0416 1994-0424 https://doaj.org/article/1bb185d3c88a4591bac04951ce34564c The Cryosphere, Vol 16, Pp 4537-4552 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-4537-2022 2022-12-30T20:55:31Z 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 Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Weertman ENVELOPE(-67.753,-67.753,-66.972,-66.972) The Cryosphere 16 10 4537 4552 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 E. Kazmierczak S. Sun V. Coulon F. Pattyn Subglacial hydrology modulates basal sliding response of the Antarctic ice sheet to climate forcing |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
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 |
E. Kazmierczak S. Sun V. Coulon F. Pattyn |
author_facet |
E. Kazmierczak S. Sun V. Coulon F. Pattyn |
author_sort |
E. Kazmierczak |
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 |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-4537-2022 https://doaj.org/article/1bb185d3c88a4591bac04951ce34564c |
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_source |
The Cryosphere, Vol 16, Pp 4537-4552 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/4537/2022/tc-16-4537-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4537-2022 1994-0416 1994-0424 https://doaj.org/article/1bb185d3c88a4591bac04951ce34564c |
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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1766275515929329664 |