Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations
ABSTRACT Ice-shelf basal melting is the largest contributor to the negative mass balance of the Antarctic ice sheet. However, current implementations of ice/ocean interactions in ice-sheet models disagree with the distribution of sub-shelf melt and freezing rates revealed by recent observational stu...
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/jog.2017.42 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000429 |
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crcambridgeupr:10.1017/jog.2017.42 2024-05-19T07:30:37+00:00 Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations BERNALES, JORGE ROGOZHINA, IRINA THOMAS, MAIK 2017 http://dx.doi.org/10.1017/jog.2017.42 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000429 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by-nc-nd/4.0/ Journal of Glaciology volume 63, issue 240, page 731-744 ISSN 0022-1430 1727-5652 journal-article 2017 crcambridgeupr https://doi.org/10.1017/jog.2017.42 2024-04-25T06:51:18Z ABSTRACT Ice-shelf basal melting is the largest contributor to the negative mass balance of the Antarctic ice sheet. However, current implementations of ice/ocean interactions in ice-sheet models disagree with the distribution of sub-shelf melt and freezing rates revealed by recent observational studies. Here we present a novel combination of a continental-scale ice flow model and a calibration technique to derive the spatial distribution of basal melting and freezing rates for the whole Antarctic ice-shelf system. The modelled ice-sheet equilibrium state is evaluated against topographic and velocity observations. Our high-resolution (10-km spacing) simulation predicts an equilibrium ice-shelf basal mass balance of −1648.7 Gt a −1 that increases to −1917.0 Gt a −1 when the observed ice-shelf thinning rates are taken into account. Our estimates reproduce the complexity of the basal mass balance of Antarctic ice shelves, providing a reference for parameterisations of sub-shelf ocean/ice interactions in continental ice-sheet models. We perform a sensitivity analysis to assess the effects of variations in the model set-up, showing that the retrieved estimates of basal melting and freezing rates are largely insensitive to changes in the internal model parameters, but respond strongly to a reduction of model resolution and the uncertainty in the input datasets. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Journal of Glaciology Cambridge University Press Journal of Glaciology 63 240 731 744 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
ABSTRACT Ice-shelf basal melting is the largest contributor to the negative mass balance of the Antarctic ice sheet. However, current implementations of ice/ocean interactions in ice-sheet models disagree with the distribution of sub-shelf melt and freezing rates revealed by recent observational studies. Here we present a novel combination of a continental-scale ice flow model and a calibration technique to derive the spatial distribution of basal melting and freezing rates for the whole Antarctic ice-shelf system. The modelled ice-sheet equilibrium state is evaluated against topographic and velocity observations. Our high-resolution (10-km spacing) simulation predicts an equilibrium ice-shelf basal mass balance of −1648.7 Gt a −1 that increases to −1917.0 Gt a −1 when the observed ice-shelf thinning rates are taken into account. Our estimates reproduce the complexity of the basal mass balance of Antarctic ice shelves, providing a reference for parameterisations of sub-shelf ocean/ice interactions in continental ice-sheet models. We perform a sensitivity analysis to assess the effects of variations in the model set-up, showing that the retrieved estimates of basal melting and freezing rates are largely insensitive to changes in the internal model parameters, but respond strongly to a reduction of model resolution and the uncertainty in the input datasets. |
format |
Article in Journal/Newspaper |
author |
BERNALES, JORGE ROGOZHINA, IRINA THOMAS, MAIK |
spellingShingle |
BERNALES, JORGE ROGOZHINA, IRINA THOMAS, MAIK Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations |
author_facet |
BERNALES, JORGE ROGOZHINA, IRINA THOMAS, MAIK |
author_sort |
BERNALES, JORGE |
title |
Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations |
title_short |
Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations |
title_full |
Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations |
title_fullStr |
Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations |
title_full_unstemmed |
Melting and freezing under Antarctic ice shelves from a combination of ice-sheet modelling and observations |
title_sort |
melting and freezing under antarctic ice shelves from a combination of ice-sheet modelling and observations |
publisher |
Cambridge University Press (CUP) |
publishDate |
2017 |
url |
http://dx.doi.org/10.1017/jog.2017.42 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000429 |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Journal of Glaciology |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Journal of Glaciology |
op_source |
Journal of Glaciology volume 63, issue 240, page 731-744 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2017.42 |
container_title |
Journal of Glaciology |
container_volume |
63 |
container_issue |
240 |
container_start_page |
731 |
op_container_end_page |
744 |
_version_ |
1799487890889113600 |