Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian
We present depth profiles of Cd isotopes and concentrations from the Southern Ocean at four stations in the Atlantic sector along the Greenwich Meridian (47 degrees S to 68 degrees S) located across the main Antarctic frontal zones and productivity belt. The vertical profiles of Cd concentration typ...
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ftpubman:oai:pure.mpg.de:item_2084340 2024-09-15T17:42:23+00:00 Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian Abouchami, W. Galer, S. de Baar, H. Middag, R. Vance, D. Zhao, Y. Klunder, M. Mezger, K. Feldmann, H. Andreae, M. 2014 http://hdl.handle.net/11858/00-001M-0000-0024-9CEC-5 unknown info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gca.2013.10.022 http://hdl.handle.net/11858/00-001M-0000-0024-9CEC-5 Geochimica et Cosmochimica Acta info:eu-repo/semantics/article 2014 ftpubman https://doi.org/10.1016/j.gca.2013.10.022 2024-07-31T09:31:28Z We present depth profiles of Cd isotopes and concentrations from the Southern Ocean at four stations in the Atlantic sector along the Greenwich Meridian (47 degrees S to 68 degrees S) located across the main Antarctic frontal zones and productivity belt. The vertical profiles of Cd concentration typically show low values in surface waters, elevated values at intermediate depths, reflecting remineralization of sinking particulate organic matter, and constant values in deep waters. The surface-to-deep isotopic gradient shows "heavy" Cd isotope signatures in the mixed surface layer, becoming more pronounced northward, with values up to epsilon(112/110) Cd of around +4.1 in the Subantarctic sector of the Southern Ocean. Deep Antarctic waters display a uniform and "light" epsilon(112/110) Cd of +1.18 +/- 0.38 and Cd concentrations of 0.761 +/- 0.101 nmol/kg (n = 23, 2SD). Intermediate waters are characterized by epsilon(112/110) Cd lying between those of surface and deep waters, with a constant value of about +0.8 in the High Nutrient Low Chlorophyll sector and a notably higher value of +2.3 in the Subantarctic sector. The Cd isotope fractionation in the Southern Ocean closely follows a simple closed-system Rayleigh model, in which biological uptake of Cd imparts the epsilon(112/110) Cd signature to the surface layer while that of deep waters is determined by the flux of regenerated isotopically-light Cd from sinking organic matter from the surface ocean and the degree of mixing of distinct water masses. The vertical gradient documented for Cd isotopes and nutrient ratios, along with the meridional gradient in surface waters, highlights the important role played by upwelling in the Southern Ocean in closing the meridional overturning circulation via the export of Antarctic intermediate and mode waters which have a distinctive chemical (low Cd:P) and Cd isotope ("heavy") signature. The combined Cd-Zn isotope systematics provide evidence for a strong link between the magnitude of biological Cd stable isotope ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Max Planck Society: MPG.PuRe Geochimica et Cosmochimica Acta 127 348 367 |
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Open Polar |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
unknown |
description |
We present depth profiles of Cd isotopes and concentrations from the Southern Ocean at four stations in the Atlantic sector along the Greenwich Meridian (47 degrees S to 68 degrees S) located across the main Antarctic frontal zones and productivity belt. The vertical profiles of Cd concentration typically show low values in surface waters, elevated values at intermediate depths, reflecting remineralization of sinking particulate organic matter, and constant values in deep waters. The surface-to-deep isotopic gradient shows "heavy" Cd isotope signatures in the mixed surface layer, becoming more pronounced northward, with values up to epsilon(112/110) Cd of around +4.1 in the Subantarctic sector of the Southern Ocean. Deep Antarctic waters display a uniform and "light" epsilon(112/110) Cd of +1.18 +/- 0.38 and Cd concentrations of 0.761 +/- 0.101 nmol/kg (n = 23, 2SD). Intermediate waters are characterized by epsilon(112/110) Cd lying between those of surface and deep waters, with a constant value of about +0.8 in the High Nutrient Low Chlorophyll sector and a notably higher value of +2.3 in the Subantarctic sector. The Cd isotope fractionation in the Southern Ocean closely follows a simple closed-system Rayleigh model, in which biological uptake of Cd imparts the epsilon(112/110) Cd signature to the surface layer while that of deep waters is determined by the flux of regenerated isotopically-light Cd from sinking organic matter from the surface ocean and the degree of mixing of distinct water masses. The vertical gradient documented for Cd isotopes and nutrient ratios, along with the meridional gradient in surface waters, highlights the important role played by upwelling in the Southern Ocean in closing the meridional overturning circulation via the export of Antarctic intermediate and mode waters which have a distinctive chemical (low Cd:P) and Cd isotope ("heavy") signature. The combined Cd-Zn isotope systematics provide evidence for a strong link between the magnitude of biological Cd stable isotope ... |
format |
Article in Journal/Newspaper |
author |
Abouchami, W. Galer, S. de Baar, H. Middag, R. Vance, D. Zhao, Y. Klunder, M. Mezger, K. Feldmann, H. Andreae, M. |
spellingShingle |
Abouchami, W. Galer, S. de Baar, H. Middag, R. Vance, D. Zhao, Y. Klunder, M. Mezger, K. Feldmann, H. Andreae, M. Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian |
author_facet |
Abouchami, W. Galer, S. de Baar, H. Middag, R. Vance, D. Zhao, Y. Klunder, M. Mezger, K. Feldmann, H. Andreae, M. |
author_sort |
Abouchami, W. |
title |
Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian |
title_short |
Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian |
title_full |
Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian |
title_fullStr |
Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian |
title_full_unstemmed |
Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian |
title_sort |
biogeochemical cycling of cadmium isotopes in the southern ocean along the zero meridian |
publishDate |
2014 |
url |
http://hdl.handle.net/11858/00-001M-0000-0024-9CEC-5 |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Geochimica et Cosmochimica Acta |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gca.2013.10.022 http://hdl.handle.net/11858/00-001M-0000-0024-9CEC-5 |
op_doi |
https://doi.org/10.1016/j.gca.2013.10.022 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
127 |
container_start_page |
348 |
op_container_end_page |
367 |
_version_ |
1810488938358374400 |