Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year
Meridional and vertical distributions of several biogeochemical parameters were studied along a section in the southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer 2008 of the International Polar Year to characterize the biogeochemical provinces and to assess...
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Format: | Article in Journal/Newspaper |
Language: | English |
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Copernicus Publications (EGU)
2013
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Online Access: | https://oceanrep.geomar.de/id/eprint/26316/ https://oceanrep.geomar.de/id/eprint/26316/1/bg-10-281-2013.pdf https://doi.org/10.5194/bg-10-281-2013 |
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ftoceanrep:oai:oceanrep.geomar.de:26316 2023-05-15T13:57:35+02:00 Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year Le Moigne, Frederic A. C. Boye, M. Masson, A. Corvaisier, R. Grossteffan, E. Guéneugues, A. Pondaven, P. 2013 text https://oceanrep.geomar.de/id/eprint/26316/ https://oceanrep.geomar.de/id/eprint/26316/1/bg-10-281-2013.pdf https://doi.org/10.5194/bg-10-281-2013 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/26316/1/bg-10-281-2013.pdf Le Moigne, F. A. C. , Boye, M., Masson, A., Corvaisier, R., Grossteffan, E., Guéneugues, A. and Pondaven, P. (2013) Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year. Open Access Biogeosciences (BG), 10 (1). pp. 281-295. DOI 10.5194/bg-10-281-2013 <https://doi.org/10.5194/bg-10-281-2013>. doi:10.5194/bg-10-281-2013 cc_by info:eu-repo/semantics/openAccess Article PeerReviewed 2013 ftoceanrep https://doi.org/10.5194/bg-10-281-2013 2023-04-07T15:15:41Z Meridional and vertical distributions of several biogeochemical parameters were studied along a section in the southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer 2008 of the International Polar Year to characterize the biogeochemical provinces and to assess the seasonal net diatom production. Based on analyses of macro-nutrients, ammonium (NH4), chlorophyll a, (Chl a), phaeopigments, biogenic silica (BSi), particulate inorganic carbon (PIC), and particulate organic carbon and nitrogen (POC and PON, respectively), four biogeochemical domains were distinguished along the section: the subtropical Atlantic, the confluence zone of the subtropical and subantarctic domains, the Polar Frontal Zone (PFZ) in the Antarctic Circumpolar Current (ACC), and the north-eastern branch of the Weddell Gyre. The subtropical region displayed extremely low nutrient concentrations featuring oligotrophic conditions, and sub-surface maxima of Chl a and phaeopigments never exceeded 0.5 µg L−1 and 0.25 µg L−1, respectively. The anticyclonic and cyclonic eddies crossed in the Cape Basin were characterized by a deepening and a rise, respectively, of the nutrients isoclines. The confluence zone of the subtropical domain and the northern side of the ACC within the subantarctic domain displayed remnant nitrate and phosphate levels, whereas silicate concentrations kept to extremely low levels. In this area, Chl a level of 0.4–0.5 µg L−1 distributed homogenously within the mixed layer, and POC and PON accumulated to values up to 10 µM and 1.5 µM, respectively, indicative of biomass accumulation along the confluence zone during the late productive period. In the ACC domain, the Polar Frontal Zone was marked by a post-bloom of diatoms that extended beyond the Polar Front (PF) during this late summer condition, as primarily evidenced by the massive depletion of silicic acid in the surface waters. The accumulation of NH4 to values up to 1.25 µM at 100 m depth centred on the PF and the accumulation of BSi up ... Article in Journal/Newspaper Antarc* Antarctic International Polar Year Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Southern Ocean The Antarctic Austral Weddell Biogeosciences 10 1 281 295 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Meridional and vertical distributions of several biogeochemical parameters were studied along a section in the southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer 2008 of the International Polar Year to characterize the biogeochemical provinces and to assess the seasonal net diatom production. Based on analyses of macro-nutrients, ammonium (NH4), chlorophyll a, (Chl a), phaeopigments, biogenic silica (BSi), particulate inorganic carbon (PIC), and particulate organic carbon and nitrogen (POC and PON, respectively), four biogeochemical domains were distinguished along the section: the subtropical Atlantic, the confluence zone of the subtropical and subantarctic domains, the Polar Frontal Zone (PFZ) in the Antarctic Circumpolar Current (ACC), and the north-eastern branch of the Weddell Gyre. The subtropical region displayed extremely low nutrient concentrations featuring oligotrophic conditions, and sub-surface maxima of Chl a and phaeopigments never exceeded 0.5 µg L−1 and 0.25 µg L−1, respectively. The anticyclonic and cyclonic eddies crossed in the Cape Basin were characterized by a deepening and a rise, respectively, of the nutrients isoclines. The confluence zone of the subtropical domain and the northern side of the ACC within the subantarctic domain displayed remnant nitrate and phosphate levels, whereas silicate concentrations kept to extremely low levels. In this area, Chl a level of 0.4–0.5 µg L−1 distributed homogenously within the mixed layer, and POC and PON accumulated to values up to 10 µM and 1.5 µM, respectively, indicative of biomass accumulation along the confluence zone during the late productive period. In the ACC domain, the Polar Frontal Zone was marked by a post-bloom of diatoms that extended beyond the Polar Front (PF) during this late summer condition, as primarily evidenced by the massive depletion of silicic acid in the surface waters. The accumulation of NH4 to values up to 1.25 µM at 100 m depth centred on the PF and the accumulation of BSi up ... |
format |
Article in Journal/Newspaper |
author |
Le Moigne, Frederic A. C. Boye, M. Masson, A. Corvaisier, R. Grossteffan, E. Guéneugues, A. Pondaven, P. |
spellingShingle |
Le Moigne, Frederic A. C. Boye, M. Masson, A. Corvaisier, R. Grossteffan, E. Guéneugues, A. Pondaven, P. Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year |
author_facet |
Le Moigne, Frederic A. C. Boye, M. Masson, A. Corvaisier, R. Grossteffan, E. Guéneugues, A. Pondaven, P. |
author_sort |
Le Moigne, Frederic A. C. |
title |
Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year |
title_short |
Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year |
title_full |
Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year |
title_fullStr |
Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year |
title_full_unstemmed |
Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year |
title_sort |
description of the biogeochemical features of the subtropical southeastern atlantic and the southern ocean south of south africa during the austral summer of the international polar year |
publisher |
Copernicus Publications (EGU) |
publishDate |
2013 |
url |
https://oceanrep.geomar.de/id/eprint/26316/ https://oceanrep.geomar.de/id/eprint/26316/1/bg-10-281-2013.pdf https://doi.org/10.5194/bg-10-281-2013 |
geographic |
Antarctic Southern Ocean The Antarctic Austral Weddell |
geographic_facet |
Antarctic Southern Ocean The Antarctic Austral Weddell |
genre |
Antarc* Antarctic International Polar Year Southern Ocean |
genre_facet |
Antarc* Antarctic International Polar Year Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/26316/1/bg-10-281-2013.pdf Le Moigne, F. A. C. , Boye, M., Masson, A., Corvaisier, R., Grossteffan, E., Guéneugues, A. and Pondaven, P. (2013) Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year. Open Access Biogeosciences (BG), 10 (1). pp. 281-295. DOI 10.5194/bg-10-281-2013 <https://doi.org/10.5194/bg-10-281-2013>. doi:10.5194/bg-10-281-2013 |
op_rights |
cc_by info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-10-281-2013 |
container_title |
Biogeosciences |
container_volume |
10 |
container_issue |
1 |
container_start_page |
281 |
op_container_end_page |
295 |
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1766265282974711808 |