Sub-ice platelet layer physics: insights from a mushy-layer sea ice model
The sub-ice platelet layer (SIPL) is a highly porous, isothermal, friable layer of ice crystals and saltwater, that can develop to several meters in thickness under consolidated sea ice near Antarctic ice shelves. While the SIPL has been comprehensively described, details of its physics are rather p...
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Online Access: | https://doi.org/10.1029/2019JC015918 http://ecite.utas.edu.au/144842 |
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ftunivtasecite:oai:ecite.utas.edu.au:144842 2023-05-15T13:42:40+02:00 Sub-ice platelet layer physics: insights from a mushy-layer sea ice model Wongpan, P Vancoppenolle, M Langhorne, PJ Smith, IJ Madec, G Gough, AJ Mahoney, AR Haskell, TG 2021 https://doi.org/10.1029/2019JC015918 http://ecite.utas.edu.au/144842 en eng Wiley-Blackwell Publishing, Inc. http://dx.doi.org/10.1029/2019JC015918 Wongpan, P and Vancoppenolle, M and Langhorne, PJ and Smith, IJ and Madec, G and Gough, AJ and Mahoney, AR and Haskell, TG, Sub-ice platelet layer physics: insights from a mushy-layer sea ice model, JGR Oceans, 126, (6) Article e2019JC015918. ISSN 2169-9275 (2021) [Refereed Article] http://ecite.utas.edu.au/144842 Earth Sciences Physical geography and environmental geoscience Glaciology Refereed Article PeerReviewed 2021 ftunivtasecite https://doi.org/10.1029/2019JC015918 2022-08-29T22:18:21Z The sub-ice platelet layer (SIPL) is a highly porous, isothermal, friable layer of ice crystals and saltwater, that can develop to several meters in thickness under consolidated sea ice near Antarctic ice shelves. While the SIPL has been comprehensively described, details of its physics are rather poorly understood. In this contribution we describe the halo-thermodynamic mechanisms driving the development and stability of the SIPL in mushy-layer sea ice model simulations, forced by thermal atmospheric and oceanic conditions in McMurdo Sound, Ross Sea, Antarctica. The novelty of these simulations is that they predict a realistic model analogue for the SIPL. Two aspects of the model are essential: (a) a large initial brine fraction is imposed on newly forming ice, and (b) brine rejection via advective desalination. The SIPL appears once conductive heat fluxes become insufficient to remove latent heat required to freeze the highly porous new ice. Favorable conditions for SIPL formation include cold air, supercooled waters, and consolidated ice and snow that are thick enough to provide sufficient thermal insulation. Thermohaline properties resulting from large liquid fractions stabilize the SIPL, in particular a low thermal diffusivity. Intense convection within the isothermal SIPL generates the SIPL-consolidated ice contrast without transporting heat. Using standard physical constants and free parameters, the model successfully predicts the SIPL and consolidated ice thicknesses at six locations. While most simulations were performed with 50 layers, an SIPL emerged with moderate accuracy in thickness for three layers proving a low-cost representation of the SIPL in large-scale climate models. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Shelves McMurdo Sound Ross Sea Sea ice eCite UTAS (University of Tasmania) Antarctic Ross Sea McMurdo Sound Journal of Geophysical Research: Oceans 126 6 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Physical geography and environmental geoscience Glaciology |
spellingShingle |
Earth Sciences Physical geography and environmental geoscience Glaciology Wongpan, P Vancoppenolle, M Langhorne, PJ Smith, IJ Madec, G Gough, AJ Mahoney, AR Haskell, TG Sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
topic_facet |
Earth Sciences Physical geography and environmental geoscience Glaciology |
description |
The sub-ice platelet layer (SIPL) is a highly porous, isothermal, friable layer of ice crystals and saltwater, that can develop to several meters in thickness under consolidated sea ice near Antarctic ice shelves. While the SIPL has been comprehensively described, details of its physics are rather poorly understood. In this contribution we describe the halo-thermodynamic mechanisms driving the development and stability of the SIPL in mushy-layer sea ice model simulations, forced by thermal atmospheric and oceanic conditions in McMurdo Sound, Ross Sea, Antarctica. The novelty of these simulations is that they predict a realistic model analogue for the SIPL. Two aspects of the model are essential: (a) a large initial brine fraction is imposed on newly forming ice, and (b) brine rejection via advective desalination. The SIPL appears once conductive heat fluxes become insufficient to remove latent heat required to freeze the highly porous new ice. Favorable conditions for SIPL formation include cold air, supercooled waters, and consolidated ice and snow that are thick enough to provide sufficient thermal insulation. Thermohaline properties resulting from large liquid fractions stabilize the SIPL, in particular a low thermal diffusivity. Intense convection within the isothermal SIPL generates the SIPL-consolidated ice contrast without transporting heat. Using standard physical constants and free parameters, the model successfully predicts the SIPL and consolidated ice thicknesses at six locations. While most simulations were performed with 50 layers, an SIPL emerged with moderate accuracy in thickness for three layers proving a low-cost representation of the SIPL in large-scale climate models. |
format |
Article in Journal/Newspaper |
author |
Wongpan, P Vancoppenolle, M Langhorne, PJ Smith, IJ Madec, G Gough, AJ Mahoney, AR Haskell, TG |
author_facet |
Wongpan, P Vancoppenolle, M Langhorne, PJ Smith, IJ Madec, G Gough, AJ Mahoney, AR Haskell, TG |
author_sort |
Wongpan, P |
title |
Sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
title_short |
Sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
title_full |
Sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
title_fullStr |
Sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
title_full_unstemmed |
Sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
title_sort |
sub-ice platelet layer physics: insights from a mushy-layer sea ice model |
publisher |
Wiley-Blackwell Publishing, Inc. |
publishDate |
2021 |
url |
https://doi.org/10.1029/2019JC015918 http://ecite.utas.edu.au/144842 |
geographic |
Antarctic Ross Sea McMurdo Sound |
geographic_facet |
Antarctic Ross Sea McMurdo Sound |
genre |
Antarc* Antarctic Antarctica Ice Shelves McMurdo Sound Ross Sea Sea ice |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelves McMurdo Sound Ross Sea Sea ice |
op_relation |
http://dx.doi.org/10.1029/2019JC015918 Wongpan, P and Vancoppenolle, M and Langhorne, PJ and Smith, IJ and Madec, G and Gough, AJ and Mahoney, AR and Haskell, TG, Sub-ice platelet layer physics: insights from a mushy-layer sea ice model, JGR Oceans, 126, (6) Article e2019JC015918. ISSN 2169-9275 (2021) [Refereed Article] http://ecite.utas.edu.au/144842 |
op_doi |
https://doi.org/10.1029/2019JC015918 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
126 |
container_issue |
6 |
_version_ |
1766171234293252096 |