A numerical study of the South Atlantic circulation at the Last Glacial Maximum
In this study, we examine the simulation results from the paleoclimate version of the National Center of Atmospheric Research coupled Climate System Model (CSM 1.4) for the Last Glacial Maximum (LGM) in order to understand changes in the South Atlantic (SA) circulation relative to the Present Day (P...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
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Online Access: | https://oceanrep.geomar.de/id/eprint/50478/ https://oceanrep.geomar.de/id/eprint/50478/1/Clauzet.pdf https://doi.org/10.1016/j.palaeo.2007.06.018 |
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ftoceanrep:oai:oceanrep.geomar.de:50478 2023-05-15T13:39:54+02:00 A numerical study of the South Atlantic circulation at the Last Glacial Maximum Clauzet, Gabriel Wainer, Ilana Lazar, Alban Brady, Esther Otto-Bliesner, Bette 2007-09 text https://oceanrep.geomar.de/id/eprint/50478/ https://oceanrep.geomar.de/id/eprint/50478/1/Clauzet.pdf https://doi.org/10.1016/j.palaeo.2007.06.018 en eng Elsevier https://oceanrep.geomar.de/id/eprint/50478/1/Clauzet.pdf Clauzet, G., Wainer, I., Lazar, A., Brady, E. and Otto-Bliesner, B. (2007) A numerical study of the South Atlantic circulation at the Last Glacial Maximum. Palaeogeography, Palaeoclimatology, Palaeoecology, 253 (3-4). pp. 509-528. DOI 10.1016/j.palaeo.2007.06.018 <https://doi.org/10.1016/j.palaeo.2007.06.018>. doi:10.1016/j.palaeo.2007.06.018 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2007 ftoceanrep https://doi.org/10.1016/j.palaeo.2007.06.018 2023-04-07T15:51:42Z In this study, we examine the simulation results from the paleoclimate version of the National Center of Atmospheric Research coupled Climate System Model (CSM 1.4) for the Last Glacial Maximum (LGM) in order to understand changes in the South Atlantic (SA) circulation relative to the Present Day (PD). The LGM simulation is validated with the available proxy data in the region. The results show good agreement, except in the eastern equatorial and eastern SA region, where the model is not able to reproduce the correct cloud cover and the associated air–sea interactions. Ocean transport in the PD simulation is in good agreement with observational estimates. Results show that at subsurface levels there are two distinct patterns: (i) strengthening of the transport for the LGM in the southern SA (35°S to 25°S); and (ii) weakening of the mass transport in the northern SA (25°S to the Equator). In intermediate layers, there is an intensification of the subtropical gyre and a northward shift of the South Equatorial Current (SEC) bifurcation for the LGM. This leads to the intensification of the southward transport by the Brazil Current (BC) and the associated BC recirculation cell in the southern basin for the LGM. This shift in the position of the SEC bifurcation leads to a weakening in the northward transport and the western recirculation of the central SEC in the northern basin. This northward shift of the SEC (upper limit of the subtropical gyre) is consistent with the northward shift observed in the subtropical convergence zone and suggests a displacement of the sub-tropical gyre 3°–5° towards the Equator. In deeper layers, a shallower and weaker North Atlantic Deep Water (NADW) circulation in the LGM contributes to the reduction of the southward transport in the northern part of the basin and is associated with a greater northward intrusion of Antarctic Bottom Water. This intrusion plus the increase of the Indian Water inflow is responsible for the northward transport intensification in the southern basin. Article in Journal/Newspaper Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Indian Palaeogeography, Palaeoclimatology, Palaeoecology 253 3-4 509 528 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
In this study, we examine the simulation results from the paleoclimate version of the National Center of Atmospheric Research coupled Climate System Model (CSM 1.4) for the Last Glacial Maximum (LGM) in order to understand changes in the South Atlantic (SA) circulation relative to the Present Day (PD). The LGM simulation is validated with the available proxy data in the region. The results show good agreement, except in the eastern equatorial and eastern SA region, where the model is not able to reproduce the correct cloud cover and the associated air–sea interactions. Ocean transport in the PD simulation is in good agreement with observational estimates. Results show that at subsurface levels there are two distinct patterns: (i) strengthening of the transport for the LGM in the southern SA (35°S to 25°S); and (ii) weakening of the mass transport in the northern SA (25°S to the Equator). In intermediate layers, there is an intensification of the subtropical gyre and a northward shift of the South Equatorial Current (SEC) bifurcation for the LGM. This leads to the intensification of the southward transport by the Brazil Current (BC) and the associated BC recirculation cell in the southern basin for the LGM. This shift in the position of the SEC bifurcation leads to a weakening in the northward transport and the western recirculation of the central SEC in the northern basin. This northward shift of the SEC (upper limit of the subtropical gyre) is consistent with the northward shift observed in the subtropical convergence zone and suggests a displacement of the sub-tropical gyre 3°–5° towards the Equator. In deeper layers, a shallower and weaker North Atlantic Deep Water (NADW) circulation in the LGM contributes to the reduction of the southward transport in the northern part of the basin and is associated with a greater northward intrusion of Antarctic Bottom Water. This intrusion plus the increase of the Indian Water inflow is responsible for the northward transport intensification in the southern basin. |
format |
Article in Journal/Newspaper |
author |
Clauzet, Gabriel Wainer, Ilana Lazar, Alban Brady, Esther Otto-Bliesner, Bette |
spellingShingle |
Clauzet, Gabriel Wainer, Ilana Lazar, Alban Brady, Esther Otto-Bliesner, Bette A numerical study of the South Atlantic circulation at the Last Glacial Maximum |
author_facet |
Clauzet, Gabriel Wainer, Ilana Lazar, Alban Brady, Esther Otto-Bliesner, Bette |
author_sort |
Clauzet, Gabriel |
title |
A numerical study of the South Atlantic circulation at the Last Glacial Maximum |
title_short |
A numerical study of the South Atlantic circulation at the Last Glacial Maximum |
title_full |
A numerical study of the South Atlantic circulation at the Last Glacial Maximum |
title_fullStr |
A numerical study of the South Atlantic circulation at the Last Glacial Maximum |
title_full_unstemmed |
A numerical study of the South Atlantic circulation at the Last Glacial Maximum |
title_sort |
numerical study of the south atlantic circulation at the last glacial maximum |
publisher |
Elsevier |
publishDate |
2007 |
url |
https://oceanrep.geomar.de/id/eprint/50478/ https://oceanrep.geomar.de/id/eprint/50478/1/Clauzet.pdf https://doi.org/10.1016/j.palaeo.2007.06.018 |
geographic |
Antarctic Indian |
geographic_facet |
Antarctic Indian |
genre |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/50478/1/Clauzet.pdf Clauzet, G., Wainer, I., Lazar, A., Brady, E. and Otto-Bliesner, B. (2007) A numerical study of the South Atlantic circulation at the Last Glacial Maximum. Palaeogeography, Palaeoclimatology, Palaeoecology, 253 (3-4). pp. 509-528. DOI 10.1016/j.palaeo.2007.06.018 <https://doi.org/10.1016/j.palaeo.2007.06.018>. doi:10.1016/j.palaeo.2007.06.018 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.palaeo.2007.06.018 |
container_title |
Palaeogeography, Palaeoclimatology, Palaeoecology |
container_volume |
253 |
container_issue |
3-4 |
container_start_page |
509 |
op_container_end_page |
528 |
_version_ |
1766126010560937984 |