Melting and freezing under Antarctic ice shelves from a combination of ice- sheet modelling and observations
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. Her...
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Online Access: | https://refubium.fu-berlin.de/handle/fub188/20229 https://doi.org/10.17169/refubium-23534 https://doi.org/10.1017/jog.2017.42 |
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ftfuberlin:oai:refubium.fu-berlin.de:fub188/20229 2023-05-15T13:53:47+02:00 Melting and freezing under Antarctic ice shelves from a combination of ice- sheet modelling and observations Bernales, Jorge Rogozhina, Irina Thomas, Maik 2017 14 S. application/pdf https://refubium.fu-berlin.de/handle/fub188/20229 https://doi.org/10.17169/refubium-23534 https://doi.org/10.1017/jog.2017.42 eng eng https://refubium.fu-berlin.de/handle/fub188/20229 http://dx.doi.org/10.17169/refubium-23534 doi:10.1017/jog.2017.42 http://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND ddc:550 doc-type:article 2017 ftfuberlin https://doi.org/10.17169/refubium-23534 https://doi.org/10.1017/jog.2017.42 2022-05-15T20:46:08Z 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 Freie Universität Berlin: Refubium (FU Berlin) Antarctic The Antarctic Journal of Glaciology 63 240 731 744 |
institution |
Open Polar |
collection |
Freie Universität Berlin: Refubium (FU Berlin) |
op_collection_id |
ftfuberlin |
language |
English |
topic |
ddc:550 |
spellingShingle |
ddc:550 Bernales, Jorge Rogozhina, Irina Thomas, Maik Melting and freezing under Antarctic ice shelves from a combination of ice- sheet modelling and observations |
topic_facet |
ddc:550 |
description |
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 |
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 |
publishDate |
2017 |
url |
https://refubium.fu-berlin.de/handle/fub188/20229 https://doi.org/10.17169/refubium-23534 https://doi.org/10.1017/jog.2017.42 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves |
op_relation |
https://refubium.fu-berlin.de/handle/fub188/20229 http://dx.doi.org/10.17169/refubium-23534 doi:10.1017/jog.2017.42 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.17169/refubium-23534 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_ |
1766259230972575744 |