Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S)
This paper presents the first data on the vertical distribution of chlorophyll and nutrients in the upper layers of the southern southwestern Atlantic and interprets it in relation to frontal systems and the general hydrographic features. The survey covered quasi-synoptically the area between 30 and...
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2000
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09670637_v47_n6_p1015_Brandini http://hdl.handle.net/20.500.12110/paper_09670637_v47_n6_p1015_Brandini |
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paper:paper_09670637_v47_n6_p1015_Brandini2023-06-08T15:58:41Z Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) Brazil-Malvinas Confluence Zone Chlorophyll Nutrients Polar front Southwestern Atlantic Thermal fronts Atlantic Ocean chlorophyll hydrography marine environment nutrient concentration phytoplankton chlorophyll front hydrography nutrient vertical distribution Atlantic Ocean This paper presents the first data on the vertical distribution of chlorophyll and nutrients in the upper layers of the southern southwestern Atlantic and interprets it in relation to frontal systems and the general hydrographic features. The survey covered quasi-synoptically the area between 30 and 62°S, at the beginning of the austral summers of three consecutive years (1993 through 1995). Our results show a rather consistent oceanographic structure, with similar patterns of chlorophyll and nutrient distributions with latitude. Outstanding features present throughout the three seasons are two zones of high phytoplankton production, where chlorophyll concentrations of > 1 μg/l seem to occur frequently. The first is the upper euphotic zone of the Brazil-Malvinas Confluence Zone between approximately 36 and 50°S. The second is centered on subsurface layers of the Antarctic Surface Water south of the Polar Front as far as 62°S. The rest of the area covered shows low chlorophyll concentrations (< 0.4 μg/l), due either to nutrient limitation in the oligotrophic subtropical waters of the Brazil Current or to excessive turbulence and upper-layer instability in the energetic Malvinas Current. The occurrence of a permanent meander around 38°S coincided with the cyclonic retroflexion of the Malvinas Current, causing upwelling of deep water. The ecological implications of this eddy-induced upwelling are discussed. (C) 2000 Elsevier Science Ltd. 2000 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09670637_v47_n6_p1015_Brandini http://hdl.handle.net/20.500.12110/paper_09670637_v47_n6_p1015_Brandini |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Brazil-Malvinas Confluence Zone Chlorophyll Nutrients Polar front Southwestern Atlantic Thermal fronts Atlantic Ocean chlorophyll hydrography marine environment nutrient concentration phytoplankton chlorophyll front hydrography nutrient vertical distribution Atlantic Ocean |
| spellingShingle |
Brazil-Malvinas Confluence Zone Chlorophyll Nutrients Polar front Southwestern Atlantic Thermal fronts Atlantic Ocean chlorophyll hydrography marine environment nutrient concentration phytoplankton chlorophyll front hydrography nutrient vertical distribution Atlantic Ocean Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) |
| topic_facet |
Brazil-Malvinas Confluence Zone Chlorophyll Nutrients Polar front Southwestern Atlantic Thermal fronts Atlantic Ocean chlorophyll hydrography marine environment nutrient concentration phytoplankton chlorophyll front hydrography nutrient vertical distribution Atlantic Ocean |
| description |
This paper presents the first data on the vertical distribution of chlorophyll and nutrients in the upper layers of the southern southwestern Atlantic and interprets it in relation to frontal systems and the general hydrographic features. The survey covered quasi-synoptically the area between 30 and 62°S, at the beginning of the austral summers of three consecutive years (1993 through 1995). Our results show a rather consistent oceanographic structure, with similar patterns of chlorophyll and nutrient distributions with latitude. Outstanding features present throughout the three seasons are two zones of high phytoplankton production, where chlorophyll concentrations of > 1 μg/l seem to occur frequently. The first is the upper euphotic zone of the Brazil-Malvinas Confluence Zone between approximately 36 and 50°S. The second is centered on subsurface layers of the Antarctic Surface Water south of the Polar Front as far as 62°S. The rest of the area covered shows low chlorophyll concentrations (< 0.4 μg/l), due either to nutrient limitation in the oligotrophic subtropical waters of the Brazil Current or to excessive turbulence and upper-layer instability in the energetic Malvinas Current. The occurrence of a permanent meander around 38°S coincided with the cyclonic retroflexion of the Malvinas Current, causing upwelling of deep water. The ecological implications of this eddy-induced upwelling are discussed. (C) 2000 Elsevier Science Ltd. |
| title |
Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) |
| title_short |
Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) |
| title_full |
Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) |
| title_fullStr |
Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) |
| title_full_unstemmed |
Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30-62°S) |
| title_sort |
multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern atlantic (30-62°s) |
| publishDate |
2000 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09670637_v47_n6_p1015_Brandini http://hdl.handle.net/20.500.12110/paper_09670637_v47_n6_p1015_Brandini |
| _version_ |
1768545657751076864 |