Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt
Melting underneath the floating ice shelves surrounding the Antarctic continent is a key process for the stability of the Antarctic Ice Sheet and therefore its current and future mass loss. Troughs and sills on the continental shelf play a crucial role in modulating sub-shelf melt rates, as they can...
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ftcopernicus:oai:publications.copernicus.org:egusphere115796 2023-12-31T10:00:32+01:00 Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt Nicola, Lena Reese, Ronja Kreuzer, Moritz Albrecht, Torsten Winkelmann, Ricarda 2023-11-27 application/pdf https://doi.org/10.5194/egusphere-2023-2583 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2583/ eng eng doi:10.5194/egusphere-2023-2583 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2583/ eISSN: Text 2023 ftcopernicus https://doi.org/10.5194/egusphere-2023-2583 2023-12-04T17:24:18Z Melting underneath the floating ice shelves surrounding the Antarctic continent is a key process for the stability of the Antarctic Ice Sheet and therefore its current and future mass loss. Troughs and sills on the continental shelf play a crucial role in modulating sub-shelf melt rates, as they can allow or block the access of relatively warm, modified Circumpolar Deep Water to ice-shelf cavities. Here we identify potential oceanic gateways that could allow the access of warm water masses to Antarctic grounding lines based on critical access depths inferred from high-resolution bathymetry data. We analyse the properties of water masses that are currently present in front of the ice shelf and that might intrude into the respective ice-shelf cavities in the future. We use the ice-shelf cavity model PICO to estimate an upper limit of melt rate changes in case all warm water masses up to a certain depth level gain access to the cavities. We find that melt rates could increase in all regions at least by a factor of 2. Depending on the presence or absence of an oceanic gateway and the current ice-shelf melt conditions we find up to 200-fold larger melt rates. The identification of oceanic gateways is thus valuable for assessing the potential of ice-shelf cavities to switch from a 'cold' to a 'warm' state, which could result in widespread ice loss from Antarctica. Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Copernicus Publications: E-Journals |
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Copernicus Publications: E-Journals |
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English |
description |
Melting underneath the floating ice shelves surrounding the Antarctic continent is a key process for the stability of the Antarctic Ice Sheet and therefore its current and future mass loss. Troughs and sills on the continental shelf play a crucial role in modulating sub-shelf melt rates, as they can allow or block the access of relatively warm, modified Circumpolar Deep Water to ice-shelf cavities. Here we identify potential oceanic gateways that could allow the access of warm water masses to Antarctic grounding lines based on critical access depths inferred from high-resolution bathymetry data. We analyse the properties of water masses that are currently present in front of the ice shelf and that might intrude into the respective ice-shelf cavities in the future. We use the ice-shelf cavity model PICO to estimate an upper limit of melt rate changes in case all warm water masses up to a certain depth level gain access to the cavities. We find that melt rates could increase in all regions at least by a factor of 2. Depending on the presence or absence of an oceanic gateway and the current ice-shelf melt conditions we find up to 200-fold larger melt rates. The identification of oceanic gateways is thus valuable for assessing the potential of ice-shelf cavities to switch from a 'cold' to a 'warm' state, which could result in widespread ice loss from Antarctica. |
format |
Text |
author |
Nicola, Lena Reese, Ronja Kreuzer, Moritz Albrecht, Torsten Winkelmann, Ricarda |
spellingShingle |
Nicola, Lena Reese, Ronja Kreuzer, Moritz Albrecht, Torsten Winkelmann, Ricarda Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt |
author_facet |
Nicola, Lena Reese, Ronja Kreuzer, Moritz Albrecht, Torsten Winkelmann, Ricarda |
author_sort |
Nicola, Lena |
title |
Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt |
title_short |
Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt |
title_full |
Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt |
title_fullStr |
Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt |
title_full_unstemmed |
Oceanic gateways to Antarctic grounding lines – Impact of critical access depths on sub-shelf melt |
title_sort |
oceanic gateways to antarctic grounding lines – impact of critical access depths on sub-shelf melt |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2023-2583 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2583/ |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2023-2583 https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2583/ |
op_doi |
https://doi.org/10.5194/egusphere-2023-2583 |
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1786851182281490432 |