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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Copernicus Publications
2021
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Online Access: | https://doi.org/10.5194/os-17-1067-2021 https://os.copernicus.org/articles/17/1067/2021/os-17-1067-2021.pdf https://doaj.org/article/25cc9c6302a04f92a7e7e1cbb5444e1f |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:25cc9c6302a04f92a7e7e1cbb5444e1f 2023-05-15T18:18:33+02:00 Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods C. Schmidt F. U. Schwarzkopf S. Rühs A. Biastoch 2021-08-01 https://doi.org/10.5194/os-17-1067-2021 https://os.copernicus.org/articles/17/1067/2021/os-17-1067-2021.pdf https://doaj.org/article/25cc9c6302a04f92a7e7e1cbb5444e1f en eng Copernicus Publications doi:10.5194/os-17-1067-2021 1812-0784 1812-0792 https://os.copernicus.org/articles/17/1067/2021/os-17-1067-2021.pdf https://doaj.org/article/25cc9c6302a04f92a7e7e1cbb5444e1f undefined Ocean Science, Vol 17, Pp 1067-1080 (2021) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2021 fttriple https://doi.org/10.5194/os-17-1067-2021 2023-01-22T17:51:18Z 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 Unknown Indian Ocean Science 17 4 1067 1080 |
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Open Polar |
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fttriple |
language |
English |
topic |
envir geo |
spellingShingle |
envir geo C. Schmidt F. U. Schwarzkopf S. Rühs A. Biastoch Characteristics and robustness of Agulhas leakage estimates: an inter-comparison study of Lagrangian methods |
topic_facet |
envir geo |
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. |
format |
Article in Journal/Newspaper |
author |
C. Schmidt F. U. Schwarzkopf S. Rühs A. Biastoch |
author_facet |
C. Schmidt F. U. Schwarzkopf S. Rühs A. Biastoch |
author_sort |
C. Schmidt |
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 |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/os-17-1067-2021 https://os.copernicus.org/articles/17/1067/2021/os-17-1067-2021.pdf https://doaj.org/article/25cc9c6302a04f92a7e7e1cbb5444e1f |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Ocean Science, Vol 17, Pp 1067-1080 (2021) |
op_relation |
doi:10.5194/os-17-1067-2021 1812-0784 1812-0792 https://os.copernicus.org/articles/17/1067/2021/os-17-1067-2021.pdf https://doaj.org/article/25cc9c6302a04f92a7e7e1cbb5444e1f |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/os-17-1067-2021 |
container_title |
Ocean Science |
container_volume |
17 |
container_issue |
4 |
container_start_page |
1067 |
op_container_end_page |
1080 |
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1766195150781939712 |