Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses
Gravity-driven flow of large ice masses such as the Antarctic Ice Sheet (AIS) depends on both the geometry and the mass density of the ice sheet. The vertical density profile can be approximated as pure ice overlain by a firn layer of varying thickness, and for the AIS the firn thickness is not unco...
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:51277 2023-05-15T13:51:03+02:00 Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses Schelpe, Camilla Gudmundsson, Hilmar 2023-02-01 text https://nrl.northumbria.ac.uk/id/eprint/51277/ https://doi.org/10.1029/2022jf006744 https://nrl.northumbria.ac.uk/id/eprint/51277/15/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20Into%20Large%E2%80%90Scale%20Modeling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/1/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20into%20Large%E2%80%90scale%20Modelling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/2/ManuscriptFinal.pdf en eng Wiley-Blackwell https://nrl.northumbria.ac.uk/id/eprint/51277/15/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20Into%20Large%E2%80%90Scale%20Modeling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/1/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20into%20Large%E2%80%90scale%20Modelling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/2/ManuscriptFinal.pdf Schelpe, Camilla and Gudmundsson, Hilmar (2023) Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses. Journal of Geophysical Research: Earth Surface, 128 (2). e2022JF006744. ISSN 2169-9003 cc_by_4_0 CC-BY F700 Ocean Sciences Article PeerReviewed 2023 ftunivnorthumb https://doi.org/10.1029/2022jf006744 2023-03-02T23:31:42Z Gravity-driven flow of large ice masses such as the Antarctic Ice Sheet (AIS) depends on both the geometry and the mass density of the ice sheet. The vertical density profile can be approximated as pure ice overlain by a firn layer of varying thickness, and for the AIS the firn thickness is not uncommonly 10 to 20% of the total thickness, leading to not insignificant variation in density. Nevertheless, in most vertically-integrated ice-flow models today the density is assumed constant, sometimes with an adjustment in thickness to compensate. In this study, we explore the treatment of horizontal density variations (HDVs) within vertically-integrated ice-sheet models. We assess the relative merits and shortcomings of previously proposed approaches, and provide new formulations for including HDVs. We use perturbation analysis to derive analytical solutions that describe the impact of density variations on ice flow for both grounded ice and floating ice shelves, which reveal significant qualitative differences between each of the proposed density formulations. Furthermore, by modelling the transient evolution of a large sector of the West Antarctic Ice Sheet (WAIS), we quantify the potential impact of HDVs on estimated sea level change. For the domain we considered, we find that explicitly including the horizontal density gradients in the momentum and mass conservation equations leads to about a 10% correction in the estimated change in volume above flotation over 40 years. We conclude that including horizontal density variations in flow modelling of the Antarctic Ice Sheet is important for accurate predictions of mass loss. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelves Northumbria University, Newcastle: Northumbria Research Link (NRL) Antarctic The Antarctic West Antarctic Ice Sheet Journal of Geophysical Research: Earth Surface 128 2 |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F700 Ocean Sciences |
spellingShingle |
F700 Ocean Sciences Schelpe, Camilla Gudmundsson, Hilmar Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses |
topic_facet |
F700 Ocean Sciences |
description |
Gravity-driven flow of large ice masses such as the Antarctic Ice Sheet (AIS) depends on both the geometry and the mass density of the ice sheet. The vertical density profile can be approximated as pure ice overlain by a firn layer of varying thickness, and for the AIS the firn thickness is not uncommonly 10 to 20% of the total thickness, leading to not insignificant variation in density. Nevertheless, in most vertically-integrated ice-flow models today the density is assumed constant, sometimes with an adjustment in thickness to compensate. In this study, we explore the treatment of horizontal density variations (HDVs) within vertically-integrated ice-sheet models. We assess the relative merits and shortcomings of previously proposed approaches, and provide new formulations for including HDVs. We use perturbation analysis to derive analytical solutions that describe the impact of density variations on ice flow for both grounded ice and floating ice shelves, which reveal significant qualitative differences between each of the proposed density formulations. Furthermore, by modelling the transient evolution of a large sector of the West Antarctic Ice Sheet (WAIS), we quantify the potential impact of HDVs on estimated sea level change. For the domain we considered, we find that explicitly including the horizontal density gradients in the momentum and mass conservation equations leads to about a 10% correction in the estimated change in volume above flotation over 40 years. We conclude that including horizontal density variations in flow modelling of the Antarctic Ice Sheet is important for accurate predictions of mass loss. |
format |
Article in Journal/Newspaper |
author |
Schelpe, Camilla Gudmundsson, Hilmar |
author_facet |
Schelpe, Camilla Gudmundsson, Hilmar |
author_sort |
Schelpe, Camilla |
title |
Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses |
title_short |
Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses |
title_full |
Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses |
title_fullStr |
Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses |
title_full_unstemmed |
Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses |
title_sort |
incorporating horizontal density variations into large‐scale modelling of ice masses |
publisher |
Wiley-Blackwell |
publishDate |
2023 |
url |
https://nrl.northumbria.ac.uk/id/eprint/51277/ https://doi.org/10.1029/2022jf006744 https://nrl.northumbria.ac.uk/id/eprint/51277/15/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20Into%20Large%E2%80%90Scale%20Modeling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/1/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20into%20Large%E2%80%90scale%20Modelling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/2/ManuscriptFinal.pdf |
geographic |
Antarctic The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic The Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Ice Sheet Ice Shelves |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelves |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/51277/15/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20Into%20Large%E2%80%90Scale%20Modeling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/1/JGR%20Earth%20Surface%20-%202023%20-%20Schelpe%20-%20Incorporating%20Horizontal%20Density%20Variations%20into%20Large%E2%80%90scale%20Modelling%20of%20Ice%20Masses.pdf https://nrl.northumbria.ac.uk/id/eprint/51277/2/ManuscriptFinal.pdf Schelpe, Camilla and Gudmundsson, Hilmar (2023) Incorporating Horizontal Density Variations into Large‐scale Modelling of Ice Masses. Journal of Geophysical Research: Earth Surface, 128 (2). e2022JF006744. ISSN 2169-9003 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2022jf006744 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
128 |
container_issue |
2 |
_version_ |
1766254630452330496 |