Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies
The transport of warm and salty Indian Ocean waters into the Atlantic Ocean—the Agulhas leakage—has a crucial role in the global oceanic circulation1 and thus the evolution of future climate. At present these waters provide the main source of heat and salt for the surface branch of the Atlantic meri...
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ftoceanrep:oai:oceanrep.geomar.de:5570 2023-05-15T17:34:40+02:00 Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies Biastoch, Arne Böning, Claus W. Schwarzkopf, Franziska U. Lutjeharms, J. R. E. 2009-11-26 text https://oceanrep.geomar.de/id/eprint/5570/ https://oceanrep.geomar.de/id/eprint/5570/1/1058_Biastoch_2009_IncreaseInAgulhasLeakageDue_Artzeit_pubid12583.pdf https://doi.org/10.1038/nature08519 en eng Nature Publishing Group https://oceanrep.geomar.de/id/eprint/5570/1/1058_Biastoch_2009_IncreaseInAgulhasLeakageDue_Artzeit_pubid12583.pdf Biastoch, A. , Böning, C. W. , Schwarzkopf, F. U. and Lutjeharms, J. R. E. (2009) Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies. Nature, 462 . pp. 495-498. DOI 10.1038/nature08519 <https://doi.org/10.1038/nature08519>. doi:10.1038/nature08519 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2009 ftoceanrep https://doi.org/10.1038/nature08519 2023-04-07T14:51:12Z The transport of warm and salty Indian Ocean waters into the Atlantic Ocean—the Agulhas leakage—has a crucial role in the global oceanic circulation1 and thus the evolution of future climate. At present these waters provide the main source of heat and salt for the surface branch of the Atlantic meridional overturning circulation (MOC)2. There is evidence from past glacial-to-interglacial variations in foraminiferal assemblages3 and model studies4 that the amount of Agulhas leakage and its corresponding effect on the MOC has been subject to substantial change, potentially linked to latitudinal shifts in the Southern Hemisphere westerlies5. A progressive poleward migration of the westerlies has been observed during the past two to three decades and linked to anthropogenic forcing6, but because of the sparse observational records it has not been possible to determine whether there has been a concomitant response of Agulhas leakage. Here we present the results of a high-resolution ocean general circulation model7, 8 to show that the transport of Indian Ocean waters into the South Atlantic via the Agulhas leakage has increased during the past decades in response to the change in wind forcing. The increased leakage has contributed to the observed salinification9 of South Atlantic thermocline waters. Both model and historic measurements off South America suggest that the additional Indian Ocean waters have begun to invade the North Atlantic, with potential implications for the future evolution of the MOC. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Indian Nature 462 7272 495 498 |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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English |
description |
The transport of warm and salty Indian Ocean waters into the Atlantic Ocean—the Agulhas leakage—has a crucial role in the global oceanic circulation1 and thus the evolution of future climate. At present these waters provide the main source of heat and salt for the surface branch of the Atlantic meridional overturning circulation (MOC)2. There is evidence from past glacial-to-interglacial variations in foraminiferal assemblages3 and model studies4 that the amount of Agulhas leakage and its corresponding effect on the MOC has been subject to substantial change, potentially linked to latitudinal shifts in the Southern Hemisphere westerlies5. A progressive poleward migration of the westerlies has been observed during the past two to three decades and linked to anthropogenic forcing6, but because of the sparse observational records it has not been possible to determine whether there has been a concomitant response of Agulhas leakage. Here we present the results of a high-resolution ocean general circulation model7, 8 to show that the transport of Indian Ocean waters into the South Atlantic via the Agulhas leakage has increased during the past decades in response to the change in wind forcing. The increased leakage has contributed to the observed salinification9 of South Atlantic thermocline waters. Both model and historic measurements off South America suggest that the additional Indian Ocean waters have begun to invade the North Atlantic, with potential implications for the future evolution of the MOC. |
format |
Article in Journal/Newspaper |
author |
Biastoch, Arne Böning, Claus W. Schwarzkopf, Franziska U. Lutjeharms, J. R. E. |
spellingShingle |
Biastoch, Arne Böning, Claus W. Schwarzkopf, Franziska U. Lutjeharms, J. R. E. Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies |
author_facet |
Biastoch, Arne Böning, Claus W. Schwarzkopf, Franziska U. Lutjeharms, J. R. E. |
author_sort |
Biastoch, Arne |
title |
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies |
title_short |
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies |
title_full |
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies |
title_fullStr |
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies |
title_full_unstemmed |
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies |
title_sort |
increase in agulhas leakage due to poleward shift of southern hemisphere westerlies |
publisher |
Nature Publishing Group |
publishDate |
2009 |
url |
https://oceanrep.geomar.de/id/eprint/5570/ https://oceanrep.geomar.de/id/eprint/5570/1/1058_Biastoch_2009_IncreaseInAgulhasLeakageDue_Artzeit_pubid12583.pdf https://doi.org/10.1038/nature08519 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/5570/1/1058_Biastoch_2009_IncreaseInAgulhasLeakageDue_Artzeit_pubid12583.pdf Biastoch, A. , Böning, C. W. , Schwarzkopf, F. U. and Lutjeharms, J. R. E. (2009) Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies. Nature, 462 . pp. 495-498. DOI 10.1038/nature08519 <https://doi.org/10.1038/nature08519>. doi:10.1038/nature08519 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1038/nature08519 |
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Nature |
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462 |
container_issue |
7272 |
container_start_page |
495 |
op_container_end_page |
498 |
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1766133567313674240 |