Vertical processes and resolution impact ice shelf basal melting: A multi-model study

Understanding ice shelf–ocean interaction is fundamental to projecting the Antarctic ice sheet response to a warming climate. Numerical ice shelf–ocean models are a powerful tool for simulating this interaction, yet are limited by inherent model weaknesses and scarce observations, leading to paramet...

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Main Authors: Gwyther, David E., Kusahara, Kazuya, Asay-Davis, Xylar S., Dinniman, Michael S., Galton-Fenzi, Benjamin K.
Format: Article in Journal/Newspaper
Language:English
Published: Amsterdam [u.a.] : Elsevier Science 2020
Subjects:
550
Online Access:https://oa.tib.eu/renate/handle/123456789/7551
https://doi.org/10.34657/6598
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spelling ftleibnizopen:oai:oai.leibnizopen.de:udpQoYoBbHMkKcxzhAix 2023-10-09T21:47:05+02:00 Vertical processes and resolution impact ice shelf basal melting: A multi-model study Gwyther, David E. Kusahara, Kazuya Asay-Davis, Xylar S. Dinniman, Michael S. Galton-Fenzi, Benjamin K. 2020 application/pdf https://oa.tib.eu/renate/handle/123456789/7551 https://doi.org/10.34657/6598 eng eng Amsterdam [u.a.] : Elsevier Science CC BY-NC-ND 4.0 Unported https://creativecommons.org/licenses/by-nc-nd/4.0/ Ocean modelling online 147 (2020) ice shelf–ocean interaction Intercomparison Project (ISOMIP+) ice–ocean boundary layer region 550 article Text 2020 ftleibnizopen https://doi.org/10.34657/6598 2023-09-17T23:34:47Z Understanding ice shelf–ocean interaction is fundamental to projecting the Antarctic ice sheet response to a warming climate. Numerical ice shelf–ocean models are a powerful tool for simulating this interaction, yet are limited by inherent model weaknesses and scarce observations, leading to parameterisations that are unverified and unvalidated below ice shelves. We explore how different models simulate ice shelf–ocean interaction using the 2nd Ice Shelf–Ocean Model Intercomparison Project (ISOMIP+) framework. Vertical discretisation and resolution of the ocean model are shown to have a significant effect on ice shelf basal melt rate, through differences in the distribution of meltwater fluxes and the calculation of thermal driving. Z-coordinate models, which generally have coarser vertical resolution in ice shelf cavities, may simulate higher melt rates compared to terrain-following coordinate models. This is due to the typically higher resolution of the ice–ocean boundary layer region in terrain following models, which allows better representation of a thin meltwater layer, increased stratification, and as a result, better insulation of the ice from water below. We show that a terrain-following model, a z-level coordinate model and a hybrid approach give similar results when the effective vertical resolution adjacent to the ice shelf base is similar, despite each model employing different paradigms for distributing meltwater fluxes and sampling tracers for melting. We provide a benchmark for thermodynamic ice shelf–ocean interaction with different model vertical coordinates and vertical resolutions, and suggest a framework for any future ice shelf–ocean thermodynamic parameterisations. © 2020 The Authors publishedVersion Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves LeibnizOpen (The Leibniz Association) Antarctic The Antarctic
institution Open Polar
collection LeibnizOpen (The Leibniz Association)
op_collection_id ftleibnizopen
language English
topic ice shelf–ocean interaction
Intercomparison Project (ISOMIP+)
ice–ocean boundary layer region
550
spellingShingle ice shelf–ocean interaction
Intercomparison Project (ISOMIP+)
ice–ocean boundary layer region
550
Gwyther, David E.
Kusahara, Kazuya
Asay-Davis, Xylar S.
Dinniman, Michael S.
Galton-Fenzi, Benjamin K.
Vertical processes and resolution impact ice shelf basal melting: A multi-model study
topic_facet ice shelf–ocean interaction
Intercomparison Project (ISOMIP+)
ice–ocean boundary layer region
550
description Understanding ice shelf–ocean interaction is fundamental to projecting the Antarctic ice sheet response to a warming climate. Numerical ice shelf–ocean models are a powerful tool for simulating this interaction, yet are limited by inherent model weaknesses and scarce observations, leading to parameterisations that are unverified and unvalidated below ice shelves. We explore how different models simulate ice shelf–ocean interaction using the 2nd Ice Shelf–Ocean Model Intercomparison Project (ISOMIP+) framework. Vertical discretisation and resolution of the ocean model are shown to have a significant effect on ice shelf basal melt rate, through differences in the distribution of meltwater fluxes and the calculation of thermal driving. Z-coordinate models, which generally have coarser vertical resolution in ice shelf cavities, may simulate higher melt rates compared to terrain-following coordinate models. This is due to the typically higher resolution of the ice–ocean boundary layer region in terrain following models, which allows better representation of a thin meltwater layer, increased stratification, and as a result, better insulation of the ice from water below. We show that a terrain-following model, a z-level coordinate model and a hybrid approach give similar results when the effective vertical resolution adjacent to the ice shelf base is similar, despite each model employing different paradigms for distributing meltwater fluxes and sampling tracers for melting. We provide a benchmark for thermodynamic ice shelf–ocean interaction with different model vertical coordinates and vertical resolutions, and suggest a framework for any future ice shelf–ocean thermodynamic parameterisations. © 2020 The Authors publishedVersion
format Article in Journal/Newspaper
author Gwyther, David E.
Kusahara, Kazuya
Asay-Davis, Xylar S.
Dinniman, Michael S.
Galton-Fenzi, Benjamin K.
author_facet Gwyther, David E.
Kusahara, Kazuya
Asay-Davis, Xylar S.
Dinniman, Michael S.
Galton-Fenzi, Benjamin K.
author_sort Gwyther, David E.
title Vertical processes and resolution impact ice shelf basal melting: A multi-model study
title_short Vertical processes and resolution impact ice shelf basal melting: A multi-model study
title_full Vertical processes and resolution impact ice shelf basal melting: A multi-model study
title_fullStr Vertical processes and resolution impact ice shelf basal melting: A multi-model study
title_full_unstemmed Vertical processes and resolution impact ice shelf basal melting: A multi-model study
title_sort vertical processes and resolution impact ice shelf basal melting: a multi-model study
publisher Amsterdam [u.a.] : Elsevier Science
publishDate 2020
url https://oa.tib.eu/renate/handle/123456789/7551
https://doi.org/10.34657/6598
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_source Ocean modelling online 147 (2020)
op_rights CC BY-NC-ND 4.0 Unported
https://creativecommons.org/licenses/by-nc-nd/4.0/
op_doi https://doi.org/10.34657/6598
_version_ 1779309832386379776