Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters
We analyzed 29Si of dissolved silicate for eight water column profiles across the Southern Ocean (south of Australia in spring 2001) from the Seasonal Ice Zone (SIZ) north to the Subantarctic Zone (SAZ), including the first isotopic compositions measured for Si-depleted seawaters. All profiles displ...
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Online Access: | https://doi.org/10.1029/2004GB002364 http://ecite.utas.edu.au/38794 |
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ftunivtasecite:oai:ecite.utas.edu.au:38794 2023-05-15T14:03:55+02:00 Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters Cardinal, D Alleman, LY Dehairs, F Savoye, N Trull, T Andre, L 2005 https://doi.org/10.1029/2004GB002364 http://ecite.utas.edu.au/38794 en eng American Geophysical Union http://dx.doi.org/10.1029/2004GB002364 Cardinal, D and Alleman, LY and Dehairs, F and Savoye, N and Trull, T and Andre, L, Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters, Global Biogeochemical Cycles, 19, (2) pp. GB2007. ISSN 0886-6236 (2005) [Refereed Article] http://ecite.utas.edu.au/38794 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2005 ftunivtasecite https://doi.org/10.1029/2004GB002364 2019-12-13T21:16:24Z We analyzed 29Si of dissolved silicate for eight water column profiles across the Southern Ocean (south of Australia in spring 2001) from the Seasonal Ice Zone (SIZ) north to the Subantarctic Zone (SAZ), including the first isotopic compositions measured for Si-depleted seawaters. All profiles display mixed layer enrichments in heavy Si isotopes relative to deep water in accordance with preferential uptake of the light isotope by diatoms. As silicate levels decrease from the SIZ northward across the Polar Front Zone (PFZ) to the SAZ, surface and mesopelagic 29Si signatures generally become progressively heavier, but the most Si-depleted SAZ waters do not exhibit 29Si values heavier than in the PFZ. This intricacy appears to derive from variations in the vertical and horizontal supply of silicate to surface waters, and by applying a steady state open system model, we estimate a fractionation factor, 29, between diatoms and seawater of -0.45 0.17, independently of zones and phytoplankton community. Though encouraging, these results are related to latitudinal changes in mesopelagic 29Si values, complexity in surface silicate-29Si correlations, and differences from previous studies, which underline the need for caution in the use of silicon isotopes in paleoceanographic studies until systematic efforts have been undertaken to better understand modern variations. Copyright 2005 by the American Geophysical Union. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean eCite UTAS (University of Tasmania) Antarctic Southern Ocean Global Biogeochemical Cycles 19 2 n/a n/a |
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eCite UTAS (University of Tasmania) |
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ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical Oceanography Cardinal, D Alleman, LY Dehairs, F Savoye, N Trull, T Andre, L Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
We analyzed 29Si of dissolved silicate for eight water column profiles across the Southern Ocean (south of Australia in spring 2001) from the Seasonal Ice Zone (SIZ) north to the Subantarctic Zone (SAZ), including the first isotopic compositions measured for Si-depleted seawaters. All profiles display mixed layer enrichments in heavy Si isotopes relative to deep water in accordance with preferential uptake of the light isotope by diatoms. As silicate levels decrease from the SIZ northward across the Polar Front Zone (PFZ) to the SAZ, surface and mesopelagic 29Si signatures generally become progressively heavier, but the most Si-depleted SAZ waters do not exhibit 29Si values heavier than in the PFZ. This intricacy appears to derive from variations in the vertical and horizontal supply of silicate to surface waters, and by applying a steady state open system model, we estimate a fractionation factor, 29, between diatoms and seawater of -0.45 0.17, independently of zones and phytoplankton community. Though encouraging, these results are related to latitudinal changes in mesopelagic 29Si values, complexity in surface silicate-29Si correlations, and differences from previous studies, which underline the need for caution in the use of silicon isotopes in paleoceanographic studies until systematic efforts have been undertaken to better understand modern variations. Copyright 2005 by the American Geophysical Union. |
format |
Article in Journal/Newspaper |
author |
Cardinal, D Alleman, LY Dehairs, F Savoye, N Trull, T Andre, L |
author_facet |
Cardinal, D Alleman, LY Dehairs, F Savoye, N Trull, T Andre, L |
author_sort |
Cardinal, D |
title |
Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters |
title_short |
Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters |
title_full |
Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters |
title_fullStr |
Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters |
title_full_unstemmed |
Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters |
title_sort |
relevance of silicon isotopes to si-nutrient utilization and si-source assessment in antarctic waters |
publisher |
American Geophysical Union |
publishDate |
2005 |
url |
https://doi.org/10.1029/2004GB002364 http://ecite.utas.edu.au/38794 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
http://dx.doi.org/10.1029/2004GB002364 Cardinal, D and Alleman, LY and Dehairs, F and Savoye, N and Trull, T and Andre, L, Relevance of silicon isotopes to Si-nutrient utilization and Si-source assessment in Antarctic waters, Global Biogeochemical Cycles, 19, (2) pp. GB2007. ISSN 0886-6236 (2005) [Refereed Article] http://ecite.utas.edu.au/38794 |
op_doi |
https://doi.org/10.1029/2004GB002364 |
container_title |
Global Biogeochemical Cycles |
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19 |
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2 |
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1766274796068274176 |