Antarctic sub-shelf melt rates via PICO
Ocean-induced melting below ice shelves is one of the dominant drivers for mass loss from the Antarctic Ice Sheet at present. An appropriate representation of sub-shelf melt rates is therefore essential for model simulations of marine-based ice sheet evolution. Continental-scale ice sheet models oft...
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ftleibnizopen:oai:oai.leibnizopen.de:UyaOVYsBBwLIz6xGq-qF 2023-11-12T04:00:57+01:00 Antarctic sub-shelf melt rates via PICO Reese, Ronja Albrecht, Torsten Mengel, Matthias Asay-Davis, Xylar Winkelmann, Ricarda 2018 application/pdf https://doi.org/10.34657/804 https://oa.tib.eu/renate/handle/123456789/675 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ The Cryosphere, Volume 12, Issue 6, Page 1969-1985 boundary layer grounding line ice sheet ice shelf ice-ocean interaction iceberg calving oceanic circulation two-dimensional modeling 550 article Text 2018 ftleibnizopen https://doi.org/10.34657/804 2023-10-22T23:27:10Z Ocean-induced melting below ice shelves is one of the dominant drivers for mass loss from the Antarctic Ice Sheet at present. An appropriate representation of sub-shelf melt rates is therefore essential for model simulations of marine-based ice sheet evolution. Continental-scale ice sheet models often rely on simple melt-parameterizations, in particular for long-term simulations, when fully coupled ice–ocean interaction becomes computationally too expensive. Such parameterizations can account for the influence of the local depth of the ice-shelf draft or its slope on melting. However, they do not capture the effect of ocean circulation underneath the ice shelf. Here we present the Potsdam Ice-shelf Cavity mOdel (PICO), which simulates the vertical overturning circulation in ice-shelf cavities and thus enables the computation of sub-shelf melt rates consistent with this circulation. PICO is based on an ocean box model that coarsely resolves ice shelf cavities and uses a boundary layer melt formulation. We implement it as a module of the Parallel Ice Sheet Model (PISM) and evaluate its performance under present-day conditions of the Southern Ocean. We identify a set of parameters that yield two-dimensional melt rate fields that qualitatively reproduce the typical pattern of comparably high melting near the grounding line and lower melting or refreezing towards the calving front. PICO captures the wide range of melt rates observed for Antarctic ice shelves, with an average of about 0.1 m a−1 for cold sub-shelf cavities, for example, underneath Ross or Ronne ice shelves, to 16 m a−1 for warm cavities such as in the Amundsen Sea region. This makes PICO a computationally feasible and more physical alternative to melt parameterizations purely based on ice draft geometry. publishedVersion Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Iceberg* Southern Ocean The Cryosphere Unknown Amundsen Sea Antarctic Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
boundary layer grounding line ice sheet ice shelf ice-ocean interaction iceberg calving oceanic circulation two-dimensional modeling 550 |
spellingShingle |
boundary layer grounding line ice sheet ice shelf ice-ocean interaction iceberg calving oceanic circulation two-dimensional modeling 550 Reese, Ronja Albrecht, Torsten Mengel, Matthias Asay-Davis, Xylar Winkelmann, Ricarda Antarctic sub-shelf melt rates via PICO |
topic_facet |
boundary layer grounding line ice sheet ice shelf ice-ocean interaction iceberg calving oceanic circulation two-dimensional modeling 550 |
description |
Ocean-induced melting below ice shelves is one of the dominant drivers for mass loss from the Antarctic Ice Sheet at present. An appropriate representation of sub-shelf melt rates is therefore essential for model simulations of marine-based ice sheet evolution. Continental-scale ice sheet models often rely on simple melt-parameterizations, in particular for long-term simulations, when fully coupled ice–ocean interaction becomes computationally too expensive. Such parameterizations can account for the influence of the local depth of the ice-shelf draft or its slope on melting. However, they do not capture the effect of ocean circulation underneath the ice shelf. Here we present the Potsdam Ice-shelf Cavity mOdel (PICO), which simulates the vertical overturning circulation in ice-shelf cavities and thus enables the computation of sub-shelf melt rates consistent with this circulation. PICO is based on an ocean box model that coarsely resolves ice shelf cavities and uses a boundary layer melt formulation. We implement it as a module of the Parallel Ice Sheet Model (PISM) and evaluate its performance under present-day conditions of the Southern Ocean. We identify a set of parameters that yield two-dimensional melt rate fields that qualitatively reproduce the typical pattern of comparably high melting near the grounding line and lower melting or refreezing towards the calving front. PICO captures the wide range of melt rates observed for Antarctic ice shelves, with an average of about 0.1 m a−1 for cold sub-shelf cavities, for example, underneath Ross or Ronne ice shelves, to 16 m a−1 for warm cavities such as in the Amundsen Sea region. This makes PICO a computationally feasible and more physical alternative to melt parameterizations purely based on ice draft geometry. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Reese, Ronja Albrecht, Torsten Mengel, Matthias Asay-Davis, Xylar Winkelmann, Ricarda |
author_facet |
Reese, Ronja Albrecht, Torsten Mengel, Matthias Asay-Davis, Xylar Winkelmann, Ricarda |
author_sort |
Reese, Ronja |
title |
Antarctic sub-shelf melt rates via PICO |
title_short |
Antarctic sub-shelf melt rates via PICO |
title_full |
Antarctic sub-shelf melt rates via PICO |
title_fullStr |
Antarctic sub-shelf melt rates via PICO |
title_full_unstemmed |
Antarctic sub-shelf melt rates via PICO |
title_sort |
antarctic sub-shelf melt rates via pico |
publisher |
München : European Geopyhsical Union |
publishDate |
2018 |
url |
https://doi.org/10.34657/804 https://oa.tib.eu/renate/handle/123456789/675 |
geographic |
Amundsen Sea Antarctic Southern Ocean The Antarctic |
geographic_facet |
Amundsen Sea Antarctic Southern Ocean The Antarctic |
genre |
Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Iceberg* Southern Ocean The Cryosphere |
genre_facet |
Amundsen Sea Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Iceberg* Southern Ocean The Cryosphere |
op_source |
The Cryosphere, Volume 12, Issue 6, Page 1969-1985 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/804 |
_version_ |
1782329060307763200 |