Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes
Basal melting below ice shelves is a major factor in mass loss from the Antarctic Ice Sheet, which can contribute significantly to possible future sea-level rise. Therefore, it is important to have an adequate description of the basal melt rates for use in ice-dynamical models. Most current ice mode...
Main Authors: | , , , |
---|---|
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://dspace.library.uu.nl/handle/1874/361688 |
id |
ftunivutrecht:oai:dspace.library.uu.nl:1874/361688 |
---|---|
record_format |
openpolar |
spelling |
ftunivutrecht:oai:dspace.library.uu.nl:1874/361688 2023-07-23T04:15:47+02:00 Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes Lazeroms, Werner M.J. Jenkins, Adrian Gudmundsson, Hilmar Van De Wal, Roderik S.W. Sub Dynamics Meteorology Marine and Atmospheric Research 2018-01-09 image/pdf https://dspace.library.uu.nl/handle/1874/361688 en eng 1994-0416 https://dspace.library.uu.nl/handle/1874/361688 info:eu-repo/semantics/OpenAccess Water Science and Technology Earth-Surface Processes Article 2018 ftunivutrecht 2023-07-02T02:23:00Z Basal melting below ice shelves is a major factor in mass loss from the Antarctic Ice Sheet, which can contribute significantly to possible future sea-level rise. Therefore, it is important to have an adequate description of the basal melt rates for use in ice-dynamical models. Most current ice models use rather simple parametrizations based on the local balance of heat between ice and ocean. In this work, however, we use a recently derived parametrization of the melt rates based on a buoyant meltwater plume travelling upward beneath an ice shelf. This plume parametrization combines a non-linear ocean temperature sensitivity with an inherent geometry dependence, which is mainly described by the grounding-line depth and the local slope of the ice-shelf base. For the first time, this type of parametrization is evaluated on a two-dimensional grid covering the entire Antarctic continent. In order to apply the essentially one-dimensional parametrization to realistic ice-shelf geometries, we present an algorithm that determines effective values for the grounding-line depth and basal slope in any point beneath an ice shelf. Furthermore, since detailed knowledge of temperatures and circulation patterns in the ice-shelf cavities is sparse or absent, we construct an effective ocean temperature field from observational data with the purpose of matching (area-averaged) melt rates from the model with observed present-day melt rates. Our results qualitatively replicate large-scale observed features in basal melt rates around Antarctica, not only in terms of average values, but also in terms of the spatial pattern, with high melt rates typically occurring near the grounding line. The plume parametrization and the effective temperature field presented here are therefore promising tools for future simulations of the Antarctic Ice Sheet requiring a more realistic oceanic forcing. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Utrecht University Repository Antarctic The Antarctic |
institution |
Open Polar |
collection |
Utrecht University Repository |
op_collection_id |
ftunivutrecht |
language |
English |
topic |
Water Science and Technology Earth-Surface Processes |
spellingShingle |
Water Science and Technology Earth-Surface Processes Lazeroms, Werner M.J. Jenkins, Adrian Gudmundsson, Hilmar Van De Wal, Roderik S.W. Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes |
topic_facet |
Water Science and Technology Earth-Surface Processes |
description |
Basal melting below ice shelves is a major factor in mass loss from the Antarctic Ice Sheet, which can contribute significantly to possible future sea-level rise. Therefore, it is important to have an adequate description of the basal melt rates for use in ice-dynamical models. Most current ice models use rather simple parametrizations based on the local balance of heat between ice and ocean. In this work, however, we use a recently derived parametrization of the melt rates based on a buoyant meltwater plume travelling upward beneath an ice shelf. This plume parametrization combines a non-linear ocean temperature sensitivity with an inherent geometry dependence, which is mainly described by the grounding-line depth and the local slope of the ice-shelf base. For the first time, this type of parametrization is evaluated on a two-dimensional grid covering the entire Antarctic continent. In order to apply the essentially one-dimensional parametrization to realistic ice-shelf geometries, we present an algorithm that determines effective values for the grounding-line depth and basal slope in any point beneath an ice shelf. Furthermore, since detailed knowledge of temperatures and circulation patterns in the ice-shelf cavities is sparse or absent, we construct an effective ocean temperature field from observational data with the purpose of matching (area-averaged) melt rates from the model with observed present-day melt rates. Our results qualitatively replicate large-scale observed features in basal melt rates around Antarctica, not only in terms of average values, but also in terms of the spatial pattern, with high melt rates typically occurring near the grounding line. The plume parametrization and the effective temperature field presented here are therefore promising tools for future simulations of the Antarctic Ice Sheet requiring a more realistic oceanic forcing. |
author2 |
Sub Dynamics Meteorology Marine and Atmospheric Research |
format |
Article in Journal/Newspaper |
author |
Lazeroms, Werner M.J. Jenkins, Adrian Gudmundsson, Hilmar Van De Wal, Roderik S.W. |
author_facet |
Lazeroms, Werner M.J. Jenkins, Adrian Gudmundsson, Hilmar Van De Wal, Roderik S.W. |
author_sort |
Lazeroms, Werner M.J. |
title |
Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes |
title_short |
Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes |
title_full |
Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes |
title_fullStr |
Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes |
title_full_unstemmed |
Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes |
title_sort |
modelling present-day basal melt rates for antarctic ice shelves using a parametrization of buoyant meltwater plumes |
publishDate |
2018 |
url |
https://dspace.library.uu.nl/handle/1874/361688 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_relation |
1994-0416 https://dspace.library.uu.nl/handle/1874/361688 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1772176793658195968 |