Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005
We describe the upper ocean thermal structure and surface nutrient concentrations between New Zealand and Antarctica along five transects that cross the Subantarctic Front, the Polar Front and the southern Antarctic Circumpolar Current front. The surface water thermal structure is coupled with varia...
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Norwegian Polar Institute
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ftjpolarres:oai:journals.openacademia.net:article/3043 2023-05-15T14:01:21+02:00 Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 Campanelli, Alessandra Massolo, Serena Grilli, Federica Marini, Mauro Paschini, Elio Rivaro, Paola Artegiani, Antonio Jacobs, Stanley S. 2011-04-13 application/pdf text/html application/epub+zip text/xml https://polarresearch.net/index.php/polar/article/view/3043 https://doi.org/10.3402/polar.v30i0.7064 eng eng Norwegian Polar Institute https://polarresearch.net/index.php/polar/article/view/3043/pdf_131 https://polarresearch.net/index.php/polar/article/view/3043/pdf_118 https://polarresearch.net/index.php/polar/article/view/3043/html_116 https://polarresearch.net/index.php/polar/article/view/3043/6879 https://polarresearch.net/index.php/polar/article/view/3043/xml_116 https://polarresearch.net/index.php/polar/article/view/3043 doi:10.3402/polar.v30i0.7064 Copyright (c) 2018 Polar Research Polar Research; Vol 30 (2011) 1751-8369 Southern Ocean nutrients silica belt Antarctic Circumpolar Current expendable bathythermograph info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2011 ftjpolarres https://doi.org/10.3402/polar.v30i0.7064 2021-11-11T19:13:37Z We describe the upper ocean thermal structure and surface nutrient concentrations between New Zealand and Antarctica along five transects that cross the Subantarctic Front, the Polar Front and the southern Antarctic Circumpolar Current front. The surface water thermal structure is coupled with variations in surface nutrient concentrations, making water masses identifiable by both temperature and nutrient ranges. In particular, a strong latitudinal gradient in orthosilicate concentration is centred at the Polar Front. On the earlier sections, which extend south-west from the Campbell Plateau, orthosilicate increases sharply southward from 10-15 to 50-55µmol l-1, between 58°S and 60°S, while surface temperature drops from 7°C to 2°C. Nitrate increases more regularly toward the south, with concentrations ranging from 10-12µmol l-1 at 54°S to 25-30µmol l-1 at 66°S. The same features are observed during the later transects between New Zealand and the Ross Sea, but the sharp silica and surface temperature gradients are shifted between 60°S and 64°S. Both temporal and spatial factors may influence the observed variability. The January transect suggests an uptake of silica, orthophosphate and nitrate between 63°S and 70°S over the intervening month, with an average depletion near 37%, 44% and 29%, respectively. An N/P apparent drawdown ratio of 8.8±4.1 and an Si/N apparent drawdown ratio >1 suggests this depletion results from a seasonal diatom bloom. A southward movement of the oceanic fronts between New Zealand and the Ross Sea relative to prior measurements is consistent with reports of recent warming and changes in the Antarctic Circumpolar Current.Keywords: Southern Ocean, nutrients, silica belt, Antarctic Circumpolar Current, expendable bathythermograph (Published: 13 April 2011) Citation: Polar Research 2011, 30, 7064, DOI:10.3402/polar.v30i0.7064 Article in Journal/Newspaper Antarc* Antarctic Antarctica Polar Research Ross Sea Southern Ocean Polar Research (E-Journal) Antarctic Southern Ocean The Antarctic Ross Sea New Zealand Campbell Plateau ENVELOPE(171.000,171.000,-50.667,-50.667) Polar Research 30 1 7064 |
institution |
Open Polar |
collection |
Polar Research (E-Journal) |
op_collection_id |
ftjpolarres |
language |
English |
topic |
Southern Ocean nutrients silica belt Antarctic Circumpolar Current expendable bathythermograph |
spellingShingle |
Southern Ocean nutrients silica belt Antarctic Circumpolar Current expendable bathythermograph Campanelli, Alessandra Massolo, Serena Grilli, Federica Marini, Mauro Paschini, Elio Rivaro, Paola Artegiani, Antonio Jacobs, Stanley S. Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 |
topic_facet |
Southern Ocean nutrients silica belt Antarctic Circumpolar Current expendable bathythermograph |
description |
We describe the upper ocean thermal structure and surface nutrient concentrations between New Zealand and Antarctica along five transects that cross the Subantarctic Front, the Polar Front and the southern Antarctic Circumpolar Current front. The surface water thermal structure is coupled with variations in surface nutrient concentrations, making water masses identifiable by both temperature and nutrient ranges. In particular, a strong latitudinal gradient in orthosilicate concentration is centred at the Polar Front. On the earlier sections, which extend south-west from the Campbell Plateau, orthosilicate increases sharply southward from 10-15 to 50-55µmol l-1, between 58°S and 60°S, while surface temperature drops from 7°C to 2°C. Nitrate increases more regularly toward the south, with concentrations ranging from 10-12µmol l-1 at 54°S to 25-30µmol l-1 at 66°S. The same features are observed during the later transects between New Zealand and the Ross Sea, but the sharp silica and surface temperature gradients are shifted between 60°S and 64°S. Both temporal and spatial factors may influence the observed variability. The January transect suggests an uptake of silica, orthophosphate and nitrate between 63°S and 70°S over the intervening month, with an average depletion near 37%, 44% and 29%, respectively. An N/P apparent drawdown ratio of 8.8±4.1 and an Si/N apparent drawdown ratio >1 suggests this depletion results from a seasonal diatom bloom. A southward movement of the oceanic fronts between New Zealand and the Ross Sea relative to prior measurements is consistent with reports of recent warming and changes in the Antarctic Circumpolar Current.Keywords: Southern Ocean, nutrients, silica belt, Antarctic Circumpolar Current, expendable bathythermograph (Published: 13 April 2011) Citation: Polar Research 2011, 30, 7064, DOI:10.3402/polar.v30i0.7064 |
format |
Article in Journal/Newspaper |
author |
Campanelli, Alessandra Massolo, Serena Grilli, Federica Marini, Mauro Paschini, Elio Rivaro, Paola Artegiani, Antonio Jacobs, Stanley S. |
author_facet |
Campanelli, Alessandra Massolo, Serena Grilli, Federica Marini, Mauro Paschini, Elio Rivaro, Paola Artegiani, Antonio Jacobs, Stanley S. |
author_sort |
Campanelli, Alessandra |
title |
Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 |
title_short |
Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 |
title_full |
Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 |
title_fullStr |
Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 |
title_full_unstemmed |
Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005 |
title_sort |
variability of nutrient and thermal structure in surface waters between new zealand and antarctica, october 2004-january 2005 |
publisher |
Norwegian Polar Institute |
publishDate |
2011 |
url |
https://polarresearch.net/index.php/polar/article/view/3043 https://doi.org/10.3402/polar.v30i0.7064 |
long_lat |
ENVELOPE(171.000,171.000,-50.667,-50.667) |
geographic |
Antarctic Southern Ocean The Antarctic Ross Sea New Zealand Campbell Plateau |
geographic_facet |
Antarctic Southern Ocean The Antarctic Ross Sea New Zealand Campbell Plateau |
genre |
Antarc* Antarctic Antarctica Polar Research Ross Sea Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Polar Research Ross Sea Southern Ocean |
op_source |
Polar Research; Vol 30 (2011) 1751-8369 |
op_relation |
https://polarresearch.net/index.php/polar/article/view/3043/pdf_131 https://polarresearch.net/index.php/polar/article/view/3043/pdf_118 https://polarresearch.net/index.php/polar/article/view/3043/html_116 https://polarresearch.net/index.php/polar/article/view/3043/6879 https://polarresearch.net/index.php/polar/article/view/3043/xml_116 https://polarresearch.net/index.php/polar/article/view/3043 doi:10.3402/polar.v30i0.7064 |
op_rights |
Copyright (c) 2018 Polar Research |
op_doi |
https://doi.org/10.3402/polar.v30i0.7064 |
container_title |
Polar Research |
container_volume |
30 |
container_issue |
1 |
container_start_page |
7064 |
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1766271095231479808 |