Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods
The inflow of relatively warm and salty water from the Indian Ocean into the South Atlantic via Agulhas leakage is important for the global overturning circulation and the global climate. In this study, we analyse the robustness of Agulhas leakage estimates as well as the thermohaline property modif...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/421494 2023-07-23T04:21:43+02:00 Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods Schmidt, Christina Schwarzkopf, Franziska U. Rühs, Siren Biastoch, Arne Sub Physical Oceanography Marine and Atmospheric Research 2021-08-16 application/pdf https://dspace.library.uu.nl/handle/1874/421494 en eng 1812-0784 https://dspace.library.uu.nl/handle/1874/421494 info:eu-repo/semantics/OpenAccess Article 2021 ftunivutrecht 2023-07-02T03:42:51Z The inflow of relatively warm and salty water from the Indian Ocean into the South Atlantic via Agulhas leakage is important for the global overturning circulation and the global climate. In this study, we analyse the robustness of Agulhas leakage estimates as well as the thermohaline property modifications of Agulhas leakage south of Africa. Lagrangian experiments with both the newly developed tool Parcels and the well established tool Ariane were performed to simulate Agulhas leakage in the eddy-rich ocean–sea-ice model INALT20 (1/20∘ horizontal resolution) forced by the JRA55-do atmospheric boundary conditions. The average transport, its variability, trend and the transit time from the Agulhas Current to the Cape Basin of Agulhas leakage is simulated comparably with both Lagrangian tools, emphasizing the robustness of our method. Different designs of the Lagrangian experiment alter in particular the total transport of Agulhas leakage by up to 2 Sv, but the variability and trend of the transport are similar across these estimates. During the transit from the Agulhas Current at 32∘ S to the Cape Basin, a cooling and freshening of Agulhas leakage waters occurs especially at the location of the Agulhas Retroflection, resulting in a density increase as the thermal effect dominates. Beyond the strong air–sea exchange around South Africa, Agulhas leakage warms and salinifies the water masses below the thermocline in the South Atlantic. Article in Journal/Newspaper Sea ice Utrecht University Repository Indian |
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Open Polar |
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Utrecht University Repository |
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ftunivutrecht |
language |
English |
description |
The inflow of relatively warm and salty water from the Indian Ocean into the South Atlantic via Agulhas leakage is important for the global overturning circulation and the global climate. In this study, we analyse the robustness of Agulhas leakage estimates as well as the thermohaline property modifications of Agulhas leakage south of Africa. Lagrangian experiments with both the newly developed tool Parcels and the well established tool Ariane were performed to simulate Agulhas leakage in the eddy-rich ocean–sea-ice model INALT20 (1/20∘ horizontal resolution) forced by the JRA55-do atmospheric boundary conditions. The average transport, its variability, trend and the transit time from the Agulhas Current to the Cape Basin of Agulhas leakage is simulated comparably with both Lagrangian tools, emphasizing the robustness of our method. Different designs of the Lagrangian experiment alter in particular the total transport of Agulhas leakage by up to 2 Sv, but the variability and trend of the transport are similar across these estimates. During the transit from the Agulhas Current at 32∘ S to the Cape Basin, a cooling and freshening of Agulhas leakage waters occurs especially at the location of the Agulhas Retroflection, resulting in a density increase as the thermal effect dominates. Beyond the strong air–sea exchange around South Africa, Agulhas leakage warms and salinifies the water masses below the thermocline in the South Atlantic. |
author2 |
Sub Physical Oceanography Marine and Atmospheric Research |
format |
Article in Journal/Newspaper |
author |
Schmidt, Christina Schwarzkopf, Franziska U. Rühs, Siren Biastoch, Arne |
spellingShingle |
Schmidt, Christina Schwarzkopf, Franziska U. Rühs, Siren Biastoch, Arne Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
author_facet |
Schmidt, Christina Schwarzkopf, Franziska U. Rühs, Siren Biastoch, Arne |
author_sort |
Schmidt, Christina |
title |
Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
title_short |
Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
title_full |
Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
title_fullStr |
Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
title_full_unstemmed |
Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
title_sort |
characteristics and robustness of agulhas leakage estimates: an inter-comparison study of lagrangian methods |
publishDate |
2021 |
url |
https://dspace.library.uu.nl/handle/1874/421494 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
1812-0784 https://dspace.library.uu.nl/handle/1874/421494 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1772187775184928768 |