An assessment of basal melt parameterisations for Antarctic ice shelves
Ocean-induced ice-shelf melt is one of the largest uncertainty factors in the Antarctic contribution to future sea-level rise. Several parameterisations exist, linking oceanic properties in front of the ice shelf to melt at the base of the ice shelf, to force ice-sheet models. Here, we assess the po...
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ftdoajarticles:oai:doaj.org/article:d1ba6f8f8f9548cfae5a658eb3e88609 2023-05-15T13:57:05+02:00 An assessment of basal melt parameterisations for Antarctic ice shelves C. Burgard N. C. Jourdain R. Reese A. Jenkins P. Mathiot 2022-12-01T00:00:00Z https://doi.org/10.5194/tc-16-4931-2022 https://doaj.org/article/d1ba6f8f8f9548cfae5a658eb3e88609 EN eng Copernicus Publications https://tc.copernicus.org/articles/16/4931/2022/tc-16-4931-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4931-2022 1994-0416 1994-0424 https://doaj.org/article/d1ba6f8f8f9548cfae5a658eb3e88609 The Cryosphere, Vol 16, Pp 4931-4975 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-4931-2022 2022-12-30T22:26:24Z Ocean-induced ice-shelf melt is one of the largest uncertainty factors in the Antarctic contribution to future sea-level rise. Several parameterisations exist, linking oceanic properties in front of the ice shelf to melt at the base of the ice shelf, to force ice-sheet models. Here, we assess the potential of a range of these existing basal melt parameterisations to emulate basal melt rates simulated by a cavity-resolving ocean model on the circum-Antarctic scale. To do so, we perform two cross-validations, over time and over ice shelves respectively, and re-tune the parameterisations in a perfect-model approach, to compare the melt rates produced by the newly tuned parameterisations to the melt rates simulated by the ocean model. We find that the quadratic dependence of melt to thermal forcing without dependency on the individual ice-shelf slope and the plume parameterisation yield the best compromise, in terms of integrated shelf melt and spatial patterns. The box parameterisation, which separates the sub-shelf circulation into boxes, the PICOP parameterisation, which combines the box and plume parameterisation, and quadratic parameterisations with dependency on the ice slope yield basal melt rates further from the model reference. The linear parameterisation cannot be recommended as the resulting integrated ice-shelf melt is comparably furthest from the reference. When using offshore hydrographic input fields in comparison to properties on the continental shelf, all parameterisations perform worse; however, the box and the slope-dependent quadratic parameterisations yield the comparably best results. In addition to the new tuning, we provide uncertainty estimates for the tuned parameters. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic The Cryosphere 16 12 4931 4975 |
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 C. Burgard N. C. Jourdain R. Reese A. Jenkins P. Mathiot An assessment of basal melt parameterisations for Antarctic ice shelves |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Ocean-induced ice-shelf melt is one of the largest uncertainty factors in the Antarctic contribution to future sea-level rise. Several parameterisations exist, linking oceanic properties in front of the ice shelf to melt at the base of the ice shelf, to force ice-sheet models. Here, we assess the potential of a range of these existing basal melt parameterisations to emulate basal melt rates simulated by a cavity-resolving ocean model on the circum-Antarctic scale. To do so, we perform two cross-validations, over time and over ice shelves respectively, and re-tune the parameterisations in a perfect-model approach, to compare the melt rates produced by the newly tuned parameterisations to the melt rates simulated by the ocean model. We find that the quadratic dependence of melt to thermal forcing without dependency on the individual ice-shelf slope and the plume parameterisation yield the best compromise, in terms of integrated shelf melt and spatial patterns. The box parameterisation, which separates the sub-shelf circulation into boxes, the PICOP parameterisation, which combines the box and plume parameterisation, and quadratic parameterisations with dependency on the ice slope yield basal melt rates further from the model reference. The linear parameterisation cannot be recommended as the resulting integrated ice-shelf melt is comparably furthest from the reference. When using offshore hydrographic input fields in comparison to properties on the continental shelf, all parameterisations perform worse; however, the box and the slope-dependent quadratic parameterisations yield the comparably best results. In addition to the new tuning, we provide uncertainty estimates for the tuned parameters. |
format |
Article in Journal/Newspaper |
author |
C. Burgard N. C. Jourdain R. Reese A. Jenkins P. Mathiot |
author_facet |
C. Burgard N. C. Jourdain R. Reese A. Jenkins P. Mathiot |
author_sort |
C. Burgard |
title |
An assessment of basal melt parameterisations for Antarctic ice shelves |
title_short |
An assessment of basal melt parameterisations for Antarctic ice shelves |
title_full |
An assessment of basal melt parameterisations for Antarctic ice shelves |
title_fullStr |
An assessment of basal melt parameterisations for Antarctic ice shelves |
title_full_unstemmed |
An assessment of basal melt parameterisations for Antarctic ice shelves |
title_sort |
assessment of basal melt parameterisations for antarctic ice shelves |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-4931-2022 https://doaj.org/article/d1ba6f8f8f9548cfae5a658eb3e88609 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves The Cryosphere |
op_source |
The Cryosphere, Vol 16, Pp 4931-4975 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/4931/2022/tc-16-4931-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4931-2022 1994-0416 1994-0424 https://doaj.org/article/d1ba6f8f8f9548cfae5a658eb3e88609 |
op_doi |
https://doi.org/10.5194/tc-16-4931-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
12 |
container_start_page |
4931 |
op_container_end_page |
4975 |
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1766264696023810048 |