Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations
Antarctica's ice shelves resist the flow of grounded ice towards the ocean through “buttressing” arising from their contact with ice rises, rumples, and lateral margins. Ice shelf thinning and retreat reduce buttressing, leading to increased delivery of mass to the ocean that adds to global sea...
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ftdoajarticles:oai:doaj.org/article:a04785557ef04f67a2171c399ecdd62d 2023-07-30T03:59:25+02:00 Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations C. Mosbeux L. Padman E. Klein P. D. Bromirski H. A. Fricker 2023-07-01T00:00:00Z https://doi.org/10.5194/tc-17-2585-2023 https://doaj.org/article/a04785557ef04f67a2171c399ecdd62d EN eng Copernicus Publications https://tc.copernicus.org/articles/17/2585/2023/tc-17-2585-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-2585-2023 1994-0416 1994-0424 https://doaj.org/article/a04785557ef04f67a2171c399ecdd62d The Cryosphere, Vol 17, Pp 2585-2606 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-2585-2023 2023-07-09T00:36:31Z Antarctica's ice shelves resist the flow of grounded ice towards the ocean through “buttressing” arising from their contact with ice rises, rumples, and lateral margins. Ice shelf thinning and retreat reduce buttressing, leading to increased delivery of mass to the ocean that adds to global sea level. Ice shelf response to large annual cycles in atmospheric and oceanic processes provides opportunities to study the dynamics of both ice shelves and the buttressed grounded ice. Here, we explore whether seasonal variability of sea surface height (SSH) can explain observed seasonal variability of ice velocity. We investigate this hypothesis using several time series of ice velocity from the Ross Ice Shelf (RIS), satellite-based estimates of SSH seaward of the RIS front, ocean models of SSH under and near RIS, and a viscous ice sheet model. The observed annual changes in RIS velocity are of the order of 1–10 m a −1 (roughly 1 % of mean flow). The ice sheet model, forced by the observed and modelled range of SSH of about 10 cm, reproduces the observed velocity changes when sufficiently large basal drag changes near the grounding line are parameterised. The model response is dominated by grounding line migration but with a significant contribution from SSH-induced tilt of the ice shelf. We expect that climate-driven changes in the seasonal cycles of winds and upper-ocean summer warming will modify the seasonal response of ice shelves to SSH and that nonlinear responses of the ice sheet will affect the longer trend in ice sheet response and its potential sea-level rise contribution. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic Ross Ice Shelf The Cryosphere 17 7 2585 2606 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 C. Mosbeux L. Padman E. Klein P. D. Bromirski H. A. Fricker Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Antarctica's ice shelves resist the flow of grounded ice towards the ocean through “buttressing” arising from their contact with ice rises, rumples, and lateral margins. Ice shelf thinning and retreat reduce buttressing, leading to increased delivery of mass to the ocean that adds to global sea level. Ice shelf response to large annual cycles in atmospheric and oceanic processes provides opportunities to study the dynamics of both ice shelves and the buttressed grounded ice. Here, we explore whether seasonal variability of sea surface height (SSH) can explain observed seasonal variability of ice velocity. We investigate this hypothesis using several time series of ice velocity from the Ross Ice Shelf (RIS), satellite-based estimates of SSH seaward of the RIS front, ocean models of SSH under and near RIS, and a viscous ice sheet model. The observed annual changes in RIS velocity are of the order of 1–10 m a −1 (roughly 1 % of mean flow). The ice sheet model, forced by the observed and modelled range of SSH of about 10 cm, reproduces the observed velocity changes when sufficiently large basal drag changes near the grounding line are parameterised. The model response is dominated by grounding line migration but with a significant contribution from SSH-induced tilt of the ice shelf. We expect that climate-driven changes in the seasonal cycles of winds and upper-ocean summer warming will modify the seasonal response of ice shelves to SSH and that nonlinear responses of the ice sheet will affect the longer trend in ice sheet response and its potential sea-level rise contribution. |
format |
Article in Journal/Newspaper |
author |
C. Mosbeux L. Padman E. Klein P. D. Bromirski H. A. Fricker |
author_facet |
C. Mosbeux L. Padman E. Klein P. D. Bromirski H. A. Fricker |
author_sort |
C. Mosbeux |
title |
Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
title_short |
Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
title_full |
Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
title_fullStr |
Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
title_full_unstemmed |
Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
title_sort |
seasonal variability in antarctic ice shelf velocities forced by sea surface height variations |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-2585-2023 https://doaj.org/article/a04785557ef04f67a2171c399ecdd62d |
geographic |
Antarctic Ross Ice Shelf |
geographic_facet |
Antarctic Ross Ice Shelf |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 2585-2606 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/2585/2023/tc-17-2585-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-2585-2023 1994-0416 1994-0424 https://doaj.org/article/a04785557ef04f67a2171c399ecdd62d |
op_doi |
https://doi.org/10.5194/tc-17-2585-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
7 |
container_start_page |
2585 |
op_container_end_page |
2606 |
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1772810242951741440 |