An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes
The interaction between ice shelves and the ocean is an important process for the development of marine ice sheets. However, it is difficult to model in full detail due to the high computational cost of coupled ice-ocean simulations, so that simplified basal-melt parameterizations are required. In t...
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American Meteorological Society
2019
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ftnerc:oai:nora.nerc.ac.uk:522310 2023-05-15T13:41:43+02:00 An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes Lazeroms, Walter M.J. Jenkins, Adrian Rienstra, Sjoerd W. van de Wal, Roderik S.W. 2019-04 text http://nora.nerc.ac.uk/id/eprint/522310/ https://nora.nerc.ac.uk/id/eprint/522310/1/jpo-d-18-0131.1.pdf https://journals.ametsoc.org/doi/abs/10.1175/JPO-D-18-0131.1 en eng American Meteorological Society https://nora.nerc.ac.uk/id/eprint/522310/1/jpo-d-18-0131.1.pdf Lazeroms, Walter M.J.; Jenkins, Adrian orcid:0000-0002-9117-0616 Rienstra, Sjoerd W.; van de Wal, Roderik S.W. 2019 An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes. Journal of Physical Oceanography, 49 (4). 917-939. https://doi.org/10.1175/JPO-D-18-0131.1 <https://doi.org/10.1175/JPO-D-18-0131.1> Publication - Article PeerReviewed 2019 ftnerc https://doi.org/10.1175/JPO-D-18-0131.1 2023-02-04T19:47:50Z The interaction between ice shelves and the ocean is an important process for the development of marine ice sheets. However, it is difficult to model in full detail due to the high computational cost of coupled ice-ocean simulations, so that simplified basal-melt parameterizations are required. In this work, a new analytical expression for basal melt is derived from the theory of buoyant meltwater plumes moving upward under the ice shelf and driving the overturning circulation within the ice-shelf cavity. The governing equations are nondimensionalized in the case of an ice shelf with constant basal slope and uniform ambient ocean conditions. An asymptotic analysis of these equations in terms of small slopes and small thermal driving, assumed typical for Antarctic ice shelves, leads to an equation that can be solved analytically for the dimensionless melt rate. This analytical expression describes a universal melt-rate curve onto which the scaled results of the original plume model collapse. Its key features are a positive melt peak close to the grounding line and a transition to refreezing further away. Comparing the analytical expression with numerical solutions of the plume model generally shows a close agreement between the two, even for more general cases than the idealized geometry considered in the derivation. The results show how the melt rates adapt naturally to changes in the geometry and ambient ocean temperature. The new expression can readily be used for improving ice-sheet models that currently still lack a sufficiently realistic description of basal melt. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Natural Environment Research Council: NERC Open Research Archive Antarctic Journal of Physical Oceanography 49 4 917 939 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The interaction between ice shelves and the ocean is an important process for the development of marine ice sheets. However, it is difficult to model in full detail due to the high computational cost of coupled ice-ocean simulations, so that simplified basal-melt parameterizations are required. In this work, a new analytical expression for basal melt is derived from the theory of buoyant meltwater plumes moving upward under the ice shelf and driving the overturning circulation within the ice-shelf cavity. The governing equations are nondimensionalized in the case of an ice shelf with constant basal slope and uniform ambient ocean conditions. An asymptotic analysis of these equations in terms of small slopes and small thermal driving, assumed typical for Antarctic ice shelves, leads to an equation that can be solved analytically for the dimensionless melt rate. This analytical expression describes a universal melt-rate curve onto which the scaled results of the original plume model collapse. Its key features are a positive melt peak close to the grounding line and a transition to refreezing further away. Comparing the analytical expression with numerical solutions of the plume model generally shows a close agreement between the two, even for more general cases than the idealized geometry considered in the derivation. The results show how the melt rates adapt naturally to changes in the geometry and ambient ocean temperature. The new expression can readily be used for improving ice-sheet models that currently still lack a sufficiently realistic description of basal melt. |
format |
Article in Journal/Newspaper |
author |
Lazeroms, Walter M.J. Jenkins, Adrian Rienstra, Sjoerd W. van de Wal, Roderik S.W. |
spellingShingle |
Lazeroms, Walter M.J. Jenkins, Adrian Rienstra, Sjoerd W. van de Wal, Roderik S.W. An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
author_facet |
Lazeroms, Walter M.J. Jenkins, Adrian Rienstra, Sjoerd W. van de Wal, Roderik S.W. |
author_sort |
Lazeroms, Walter M.J. |
title |
An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
title_short |
An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
title_full |
An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
title_fullStr |
An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
title_full_unstemmed |
An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
title_sort |
analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes |
publisher |
American Meteorological Society |
publishDate |
2019 |
url |
http://nora.nerc.ac.uk/id/eprint/522310/ https://nora.nerc.ac.uk/id/eprint/522310/1/jpo-d-18-0131.1.pdf https://journals.ametsoc.org/doi/abs/10.1175/JPO-D-18-0131.1 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves |
op_relation |
https://nora.nerc.ac.uk/id/eprint/522310/1/jpo-d-18-0131.1.pdf Lazeroms, Walter M.J.; Jenkins, Adrian orcid:0000-0002-9117-0616 Rienstra, Sjoerd W.; van de Wal, Roderik S.W. 2019 An analytical derivation of ice-shelf basal melt based on the dynamics of meltwater plumes. Journal of Physical Oceanography, 49 (4). 917-939. https://doi.org/10.1175/JPO-D-18-0131.1 <https://doi.org/10.1175/JPO-D-18-0131.1> |
op_doi |
https://doi.org/10.1175/JPO-D-18-0131.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
49 |
container_issue |
4 |
container_start_page |
917 |
op_container_end_page |
939 |
_version_ |
1766154379090460672 |