Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution
Water mass transformation (WMT) around the Antarctic margin controls Antarctica Bottom Water formation and the abyssal limb of the global meridional overturning circulation, besides mediating ocean-ice shelf exchange, ice sheet stability and its contribution to sea level rise. However, the mechanism...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5019187 2023-09-05T13:13:28+02:00 Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution Boeira Dias, F. Rintoul, S. Richter, O. Galton-Fenzi, B. Zika, J. Pellichero, V. Uotila, P. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019187 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2687 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019187 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-2687 2023-08-20T23:41:47Z Water mass transformation (WMT) around the Antarctic margin controls Antarctica Bottom Water formation and the abyssal limb of the global meridional overturning circulation, besides mediating ocean-ice shelf exchange, ice sheet stability and its contribution to sea level rise. However, the mechanisms controlling the rate of WMT in the Antarctic shelf are poorly understood due to the lack of observations and the inability of climate models to simulate those mechanisms, particularly beneath the floating ice shelves. We used a circum-Antarctic ocean-ice shelf model to assess the contribution of surface fluxes, mixing, and ocean-ice shelf interaction to the WMT on the continental shelf. The salt budget dominates the WMT rates, with the basal melt of ice shelves driving buoyancy gain at lighter density classes and salt input at coastal polynyas driving buoyancy loss at heavier densities. We found a considerable sensitivity of the WMT rates to model horizontal resolution, tides and topography within the Filchner-Ronne, East and West Antarctica ice shelf cavities. In the Filchner-Ronne Ice Shelf, an anticyclonic circulation in front of the Ronne Depression regulates the rates of basal melting/refreezing and WMT and is substantially affected by tides and model resolution. Model resolution is also found to affect the Antarctic Slope Current in both East and West Antarctica, impacting the on-shelf heat delivery, basal melt and WMT. These results highlight the importance of resolving tides and small-scale features of the flow and topography to adequately represent water mass transformations on the shelf that directly influence the abyssal global overturning circulation. Conference Object Antarc* Antarctic Antarctic Ocean Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Ronne Ice Shelf West Antarctica GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Antarctic Antarctic Ocean Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) The Antarctic West Antarctica |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
Water mass transformation (WMT) around the Antarctic margin controls Antarctica Bottom Water formation and the abyssal limb of the global meridional overturning circulation, besides mediating ocean-ice shelf exchange, ice sheet stability and its contribution to sea level rise. However, the mechanisms controlling the rate of WMT in the Antarctic shelf are poorly understood due to the lack of observations and the inability of climate models to simulate those mechanisms, particularly beneath the floating ice shelves. We used a circum-Antarctic ocean-ice shelf model to assess the contribution of surface fluxes, mixing, and ocean-ice shelf interaction to the WMT on the continental shelf. The salt budget dominates the WMT rates, with the basal melt of ice shelves driving buoyancy gain at lighter density classes and salt input at coastal polynyas driving buoyancy loss at heavier densities. We found a considerable sensitivity of the WMT rates to model horizontal resolution, tides and topography within the Filchner-Ronne, East and West Antarctica ice shelf cavities. In the Filchner-Ronne Ice Shelf, an anticyclonic circulation in front of the Ronne Depression regulates the rates of basal melting/refreezing and WMT and is substantially affected by tides and model resolution. Model resolution is also found to affect the Antarctic Slope Current in both East and West Antarctica, impacting the on-shelf heat delivery, basal melt and WMT. These results highlight the importance of resolving tides and small-scale features of the flow and topography to adequately represent water mass transformations on the shelf that directly influence the abyssal global overturning circulation. |
format |
Conference Object |
author |
Boeira Dias, F. Rintoul, S. Richter, O. Galton-Fenzi, B. Zika, J. Pellichero, V. Uotila, P. |
spellingShingle |
Boeira Dias, F. Rintoul, S. Richter, O. Galton-Fenzi, B. Zika, J. Pellichero, V. Uotila, P. Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution |
author_facet |
Boeira Dias, F. Rintoul, S. Richter, O. Galton-Fenzi, B. Zika, J. Pellichero, V. Uotila, P. |
author_sort |
Boeira Dias, F. |
title |
Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution |
title_short |
Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution |
title_full |
Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution |
title_fullStr |
Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution |
title_full_unstemmed |
Sensitivity of simulated water mass transformation on the Antarctic shelf to tides, topography and model resolution |
title_sort |
sensitivity of simulated water mass transformation on the antarctic shelf to tides, topography and model resolution |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019187 |
long_lat |
ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Antarctic Antarctic Ocean Ronne Ice Shelf The Antarctic West Antarctica |
geographic_facet |
Antarctic Antarctic Ocean Ronne Ice Shelf The Antarctic West Antarctica |
genre |
Antarc* Antarctic Antarctic Ocean Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Ronne Ice Shelf West Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Ocean Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Sheet Ice Shelf Ice Shelves Ronne Ice Shelf West Antarctica |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2687 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019187 |
op_doi |
https://doi.org/10.57757/IUGG23-2687 |
_version_ |
1776204728175165440 |