On the water masses and mean circulation of the South Atlantic Ocean
We examine recent observations of water mass distribution and circulation schemes at different depths of the South Atlantic Ocean to propose a layered, qualitative representation of the mean distribution of flow in this region. This furthers the simple upper layer geostrophic flow estimates of Peter...
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Online Access: | https://oceanrep.geomar.de/id/eprint/3555/ https://oceanrep.geomar.de/id/eprint/3555/1/Stramma99.pdf https://doi.org/10.1029/1999JC900139 |
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ftoceanrep:oai:oceanrep.geomar.de:3555 2023-05-15T13:55:16+02:00 On the water masses and mean circulation of the South Atlantic Ocean Stramma, Lothar England, Matthew 1999 text https://oceanrep.geomar.de/id/eprint/3555/ https://oceanrep.geomar.de/id/eprint/3555/1/Stramma99.pdf https://doi.org/10.1029/1999JC900139 en eng AGU (American Geophysical Union) https://oceanrep.geomar.de/id/eprint/3555/1/Stramma99.pdf Stramma, L. and England, M. (1999) On the water masses and mean circulation of the South Atlantic Ocean. Open Access Journal of Geophysical Research: Oceans, 104 . pp. 20863-20833. DOI 10.1029/1999JC900139 <https://doi.org/10.1029/1999JC900139>. doi:10.1029/1999JC900139 info:eu-repo/semantics/openAccess Article PeerReviewed 1999 ftoceanrep https://doi.org/10.1029/1999JC900139 2023-04-07T14:47:57Z We examine recent observations of water mass distribution and circulation schemes at different depths of the South Atlantic Ocean to propose a layered, qualitative representation of the mean distribution of flow in this region. This furthers the simple upper layer geostrophic flow estimates of Peterson and Stramma [1991]. In addition, we assess how well ocean general circulation models (GCMs) capture the overall structure of flow in the South Atlantic in this regard. The South Atlantic Central Water (SACW) is of South Atlantic origin in the subtropical gyre, while the SACW in the tropical region in part originates from the South Indian Ocean. The Antarctic Intermediate Water in the South Atlantic originates from a surface region of the circumpolar layer, especially in the northern Drake Passage and the Falkland Current loop, but also receives some water from the Indian Ocean. The subtropical South Atlantic above the North Atlantic Deep Water and north of the Antarctic Circumpolar Current (ACC) is dominated by the anticyclonic subtropical gyre. In the eastern tropical South Atlantic the cyclonic Angola Gyre exists, embedded in a large tropical cyclonic gyre. The equatorial part of the South Atlantic shows several depth-dependent zonal current bands besides the Angola Gyre. Ocean GCMs have difficulty capturing this detailed zonal circulation structure, even at eddy-permitting resolution. The northward extent of the subtropical gyre reduces with increasing depth, located near Brazil at 16°S in the near-surface layer and at 26°S in the Antarctic Intermediate Water layer, while the tropical cyclonic gyre progresses southward. The southward shift of the northern part of the subtropical gyre is well resolved in global ocean GCMs. However, high horizontal resolution is required to capture the South Atlantic Current north of the ACC. The North Atlantic Deep Water in the South Atlantic progresses mainly southward in the Deep Western Boundary Current, but some water also moves southward at the eastern boundary. Article in Journal/Newspaper Antarc* Antarctic Drake Passage North Atlantic Deep Water North Atlantic South Atlantic Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Drake Passage Indian The Antarctic Journal of Geophysical Research: Oceans 104 C9 20863 20883 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
We examine recent observations of water mass distribution and circulation schemes at different depths of the South Atlantic Ocean to propose a layered, qualitative representation of the mean distribution of flow in this region. This furthers the simple upper layer geostrophic flow estimates of Peterson and Stramma [1991]. In addition, we assess how well ocean general circulation models (GCMs) capture the overall structure of flow in the South Atlantic in this regard. The South Atlantic Central Water (SACW) is of South Atlantic origin in the subtropical gyre, while the SACW in the tropical region in part originates from the South Indian Ocean. The Antarctic Intermediate Water in the South Atlantic originates from a surface region of the circumpolar layer, especially in the northern Drake Passage and the Falkland Current loop, but also receives some water from the Indian Ocean. The subtropical South Atlantic above the North Atlantic Deep Water and north of the Antarctic Circumpolar Current (ACC) is dominated by the anticyclonic subtropical gyre. In the eastern tropical South Atlantic the cyclonic Angola Gyre exists, embedded in a large tropical cyclonic gyre. The equatorial part of the South Atlantic shows several depth-dependent zonal current bands besides the Angola Gyre. Ocean GCMs have difficulty capturing this detailed zonal circulation structure, even at eddy-permitting resolution. The northward extent of the subtropical gyre reduces with increasing depth, located near Brazil at 16°S in the near-surface layer and at 26°S in the Antarctic Intermediate Water layer, while the tropical cyclonic gyre progresses southward. The southward shift of the northern part of the subtropical gyre is well resolved in global ocean GCMs. However, high horizontal resolution is required to capture the South Atlantic Current north of the ACC. The North Atlantic Deep Water in the South Atlantic progresses mainly southward in the Deep Western Boundary Current, but some water also moves southward at the eastern boundary. |
format |
Article in Journal/Newspaper |
author |
Stramma, Lothar England, Matthew |
spellingShingle |
Stramma, Lothar England, Matthew On the water masses and mean circulation of the South Atlantic Ocean |
author_facet |
Stramma, Lothar England, Matthew |
author_sort |
Stramma, Lothar |
title |
On the water masses and mean circulation of the South Atlantic Ocean |
title_short |
On the water masses and mean circulation of the South Atlantic Ocean |
title_full |
On the water masses and mean circulation of the South Atlantic Ocean |
title_fullStr |
On the water masses and mean circulation of the South Atlantic Ocean |
title_full_unstemmed |
On the water masses and mean circulation of the South Atlantic Ocean |
title_sort |
on the water masses and mean circulation of the south atlantic ocean |
publisher |
AGU (American Geophysical Union) |
publishDate |
1999 |
url |
https://oceanrep.geomar.de/id/eprint/3555/ https://oceanrep.geomar.de/id/eprint/3555/1/Stramma99.pdf https://doi.org/10.1029/1999JC900139 |
geographic |
Antarctic Drake Passage Indian The Antarctic |
geographic_facet |
Antarctic Drake Passage Indian The Antarctic |
genre |
Antarc* Antarctic Drake Passage North Atlantic Deep Water North Atlantic South Atlantic Ocean |
genre_facet |
Antarc* Antarctic Drake Passage North Atlantic Deep Water North Atlantic South Atlantic Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/3555/1/Stramma99.pdf Stramma, L. and England, M. (1999) On the water masses and mean circulation of the South Atlantic Ocean. Open Access Journal of Geophysical Research: Oceans, 104 . pp. 20863-20833. DOI 10.1029/1999JC900139 <https://doi.org/10.1029/1999JC900139>. doi:10.1029/1999JC900139 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/1999JC900139 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
104 |
container_issue |
C9 |
container_start_page |
20863 |
op_container_end_page |
20883 |
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1766261646721810432 |