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...
Published in: | The Cryosphere |
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Online Access: | https://doi.org/10.5194/tc-17-2585-2023 https://tc.copernicus.org/articles/17/2585/2023/ |
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ftcopernicus:oai:publications.copernicus.org:tc105338 2023-07-30T03:57:53+02:00 Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations Mosbeux, Cyrille Padman, Laurie Klein, Emilie Bromirski, Peter D. Fricker, Helen A. 2023-07-04 application/pdf https://doi.org/10.5194/tc-17-2585-2023 https://tc.copernicus.org/articles/17/2585/2023/ eng eng doi:10.5194/tc-17-2585-2023 https://tc.copernicus.org/articles/17/2585/2023/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-17-2585-2023 2023-07-10T16:24:18Z 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. Text Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf Copernicus Publications: E-Journals Antarctic Ross Ice Shelf The Cryosphere 17 7 2585 2606 |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
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 |
Text |
author |
Mosbeux, Cyrille Padman, Laurie Klein, Emilie Bromirski, Peter D. Fricker, Helen A. |
spellingShingle |
Mosbeux, Cyrille Padman, Laurie Klein, Emilie Bromirski, Peter D. Fricker, Helen A. Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations |
author_facet |
Mosbeux, Cyrille Padman, Laurie Klein, Emilie Bromirski, Peter D. Fricker, Helen A. |
author_sort |
Mosbeux, Cyrille |
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 |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-2585-2023 https://tc.copernicus.org/articles/17/2585/2023/ |
geographic |
Antarctic Ross Ice Shelf |
geographic_facet |
Antarctic Ross Ice Shelf |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Ross Ice Shelf |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-17-2585-2023 https://tc.copernicus.org/articles/17/2585/2023/ |
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 |
_version_ |
1772820030320279552 |