Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM)
Recently, seasonal changes in sea ice cover have been found to elevate basal melt rates of the Ross Ice Shelf (RIS) calving front at sensitive regions. Melting at these sensitive regions has been found to impact ice sheet mass balance. However, the influence of these seasonally elevated basal melt r...
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Copernicus Publications
2023
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00070416 2024-01-14T10:01:23+01:00 Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) Baldacchino, Francesca Golledge, Nicholas R. Horgan, Huw Morlighem, Mathieu Alevropoulos-Borrill, Alanna V. Malyarenko, Alena Gossart, Alexandra Lowry, Daniel P. van Haastrecht, Laurine 2023-12 electronic https://doi.org/10.5194/egusphere-2023-2793 https://noa.gwlb.de/receive/cop_mods_00070416 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068765/egusphere-2023-2793.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2793/egusphere-2023-2793.pdf eng eng Copernicus Publications https://doi.org/10.5194/egusphere-2023-2793 https://noa.gwlb.de/receive/cop_mods_00070416 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068765/egusphere-2023-2793.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2793/egusphere-2023-2793.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2023 ftnonlinearchiv https://doi.org/10.5194/egusphere-2023-2793 2023-12-18T00:22:48Z Recently, seasonal changes in sea ice cover have been found to elevate basal melt rates of the Ross Ice Shelf (RIS) calving front at sensitive regions. Melting at these sensitive regions has been found to impact ice sheet mass balance. However, the influence of these seasonally elevated basal melt rates on RIS flow variability is not yet fully understood. This paper aims to explore whether seasonal perturbations in basal melt rates of the RIS can explain intra-annual variations in ice flow measured by GNSS at four sites across the ice shelf. We use the automatic differentiation tool in the Ice-sheet and Sea-level System Model (ISSM) to identify regions of the RIS where changes in basal melt affect ice velocities at the GNSS sites. Next, we seasonally perturb Massachusetts Institute of Technology general circulation (MITgcm) basal melt rates in ISSM at these sensitive regions to try and replicate the GNSS ice flow observations. The GNSS observations display clear intra-annual velocity variability at the four sites, with two distinct peaks observed in austral summer and austral winter. We can replicate this intra-annual velocity variation for GNSS sites near the calving front by seasonally perturbing the basal melt rates at the identified sensitive regions of the ice shelf. We argue that the perturbed seasonal basal melt variability at sensitive regions along the calving front is a realistic scenario for the RIS. Thus, we suggest that the GNSS-recorded intra-annual velocity variations along the calving front could be partly driven by seasonal changes in basal melting today. We also try to replicate intra-annual velocity variability observed at the Siple Coast by seasonally perturbing basal melt rates at sensitive regions there. However, we are unable to replicate similar magnitudes of velocity variations to the GNSS measurements and suspect that the perturbed seasonal basal melt variability is unrealistic, with no observations of seasonally high basal melt rates at the Siple Coast grounding lines or pinning ... Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Sea ice Niedersächsisches Online-Archiv NOA Austral Ross Ice Shelf Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Baldacchino, Francesca Golledge, Nicholas R. Horgan, Huw Morlighem, Mathieu Alevropoulos-Borrill, Alanna V. Malyarenko, Alena Gossart, Alexandra Lowry, Daniel P. van Haastrecht, Laurine Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) |
topic_facet |
article Verlagsveröffentlichung |
description |
Recently, seasonal changes in sea ice cover have been found to elevate basal melt rates of the Ross Ice Shelf (RIS) calving front at sensitive regions. Melting at these sensitive regions has been found to impact ice sheet mass balance. However, the influence of these seasonally elevated basal melt rates on RIS flow variability is not yet fully understood. This paper aims to explore whether seasonal perturbations in basal melt rates of the RIS can explain intra-annual variations in ice flow measured by GNSS at four sites across the ice shelf. We use the automatic differentiation tool in the Ice-sheet and Sea-level System Model (ISSM) to identify regions of the RIS where changes in basal melt affect ice velocities at the GNSS sites. Next, we seasonally perturb Massachusetts Institute of Technology general circulation (MITgcm) basal melt rates in ISSM at these sensitive regions to try and replicate the GNSS ice flow observations. The GNSS observations display clear intra-annual velocity variability at the four sites, with two distinct peaks observed in austral summer and austral winter. We can replicate this intra-annual velocity variation for GNSS sites near the calving front by seasonally perturbing the basal melt rates at the identified sensitive regions of the ice shelf. We argue that the perturbed seasonal basal melt variability at sensitive regions along the calving front is a realistic scenario for the RIS. Thus, we suggest that the GNSS-recorded intra-annual velocity variations along the calving front could be partly driven by seasonal changes in basal melting today. We also try to replicate intra-annual velocity variability observed at the Siple Coast by seasonally perturbing basal melt rates at sensitive regions there. However, we are unable to replicate similar magnitudes of velocity variations to the GNSS measurements and suspect that the perturbed seasonal basal melt variability is unrealistic, with no observations of seasonally high basal melt rates at the Siple Coast grounding lines or pinning ... |
format |
Article in Journal/Newspaper |
author |
Baldacchino, Francesca Golledge, Nicholas R. Horgan, Huw Morlighem, Mathieu Alevropoulos-Borrill, Alanna V. Malyarenko, Alena Gossart, Alexandra Lowry, Daniel P. van Haastrecht, Laurine |
author_facet |
Baldacchino, Francesca Golledge, Nicholas R. Horgan, Huw Morlighem, Mathieu Alevropoulos-Borrill, Alanna V. Malyarenko, Alena Gossart, Alexandra Lowry, Daniel P. van Haastrecht, Laurine |
author_sort |
Baldacchino, Francesca |
title |
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) |
title_short |
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) |
title_full |
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) |
title_fullStr |
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) |
title_full_unstemmed |
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM) |
title_sort |
modelling gnss-observed seasonal velocity changes of the ross ice shelf, antarctica, using the ice-sheet and sea-level system model (issm) |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2023-2793 https://noa.gwlb.de/receive/cop_mods_00070416 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068765/egusphere-2023-2793.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2793/egusphere-2023-2793.pdf |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
Austral Ross Ice Shelf Siple Siple Coast |
geographic_facet |
Austral Ross Ice Shelf Siple Siple Coast |
genre |
Antarc* Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Sea ice |
genre_facet |
Antarc* Antarctica Ice Sheet Ice Shelf Ross Ice Shelf Sea ice |
op_relation |
https://doi.org/10.5194/egusphere-2023-2793 https://noa.gwlb.de/receive/cop_mods_00070416 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068765/egusphere-2023-2793.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2793/egusphere-2023-2793.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/egusphere-2023-2793 |
_version_ |
1788067163293089792 |