Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean?
International audience The isotopic composition of silicic acid and biogenic Si along the WOCE SR3 transect (142-144 ̊E; spring 2001) was analysed by MC-ICP-MS, following Cardinal et al. (2003). We sampled the Subantarctic Zone (SAZ), the Subantarctic Front (SAF), the Polar Front Zone (PFZ), the Int...
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ftimtnordeurope:oai:HAL:hal-04225649v1 2024-09-30T14:21:37+00:00 Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? Cardinal, D. Alleman, L. Savoye, N. Trull, T. Dehairs, F. André, L. Centre for Energy and Environment (CERI EE - IMT Nord Europe) Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Nord Europe) Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT) Vienna, Austria 2005-04-24 https://hal.science/hal-04225649 en eng HAL CCSD Geophysical Research Abstract hal-04225649 https://hal.science/hal-04225649 Geophysical Research Abstracts, European Geoscience Union https://hal.science/hal-04225649 European Geoscience Union, Apr 2005, Vienna, Austria [SDE.MCG]Environmental Sciences/Global Changes [CHIM.ANAL]Chemical Sciences/Analytical chemistry [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDV.TOX]Life Sciences [q-bio]/Toxicology info:eu-repo/semantics/conferenceObject Conference papers 2005 ftimtnordeurope 2024-09-18T23:43:21Z International audience The isotopic composition of silicic acid and biogenic Si along the WOCE SR3 transect (142-144 ̊E; spring 2001) was analysed by MC-ICP-MS, following Cardinal et al. (2003). We sampled the Subantarctic Zone (SAZ), the Subantarctic Front (SAF), the Polar Front Zone (PFZ), the Interpolar Front Zone (IPFZ), the southern Antarctic Zone (AZ-S) and the Seasonal Ice Zone (SIZ). More than 90 seawater samples from the whole water column, including silicic acid depleted surface waters, were analysed (Cardinal et al., 2005). Furthermore, for the area between the PFZ to the SIZ we also acquired the isotopic composition of 30 surface size fractionated biogenic Si samples ( > 0.4 μ m, 20-70 μ m and > 70 μ m). No systematic isotopic fractionation was observed related to size fraction, giving con- fidence in the proxy. Biogenic Si, surface, and mesopelagic waters, display a clear latitudinal gradient of isotopic compositions becoming lighter southward of the PFZ. This gradient is much steeper for biogenic Si (0.8 p.mil variation in d29Si) than for silicic acid (0.2 p.mil). In the SAZ, surface and mesopelagic waters do not exhibit a heavier isotopic composition than in the PFZ-IPFZ, in contrast to what was expected from a global modelling study (Wischmeyer et al., 2003). By taking into account these latitudinal changes, and by applying a simple multi-box open system model we esti- mate a fractionation factor, which differs from a previous estimate for the Southern Ocean (Varela et al., 2004), but is well in accordance with the one reported for cul- tured tropical diatoms (De La Rocha et al., 1997). Only the southernmost station in the SIZ behaved differently and it is suspected that release of sea ice diatoms might have disturbed the isotopic signal. Silicic acid isotopic signatures in the deep-water column are generally homogeneous, except at the southernmost station where the imprint of newly formed Antarctic Bot- tom Water, off Adelie Land, is recorded. Overall, our results reflect latitudinal ... Conference Object Adelie Land Antarc* Antarctic Sea ice Southern Ocean HAL IMT Nord Europe - Université de Lille Antarctic Southern Ocean Varela ENVELOPE(-60.583,-60.583,-62.933,-62.933) |
institution |
Open Polar |
collection |
HAL IMT Nord Europe - Université de Lille |
op_collection_id |
ftimtnordeurope |
language |
English |
topic |
[SDE.MCG]Environmental Sciences/Global Changes [CHIM.ANAL]Chemical Sciences/Analytical chemistry [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDV.TOX]Life Sciences [q-bio]/Toxicology |
spellingShingle |
[SDE.MCG]Environmental Sciences/Global Changes [CHIM.ANAL]Chemical Sciences/Analytical chemistry [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDV.TOX]Life Sciences [q-bio]/Toxicology Cardinal, D. Alleman, L. Savoye, N. Trull, T. Dehairs, F. André, L. Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? |
topic_facet |
[SDE.MCG]Environmental Sciences/Global Changes [CHIM.ANAL]Chemical Sciences/Analytical chemistry [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDV.TOX]Life Sciences [q-bio]/Toxicology |
description |
International audience The isotopic composition of silicic acid and biogenic Si along the WOCE SR3 transect (142-144 ̊E; spring 2001) was analysed by MC-ICP-MS, following Cardinal et al. (2003). We sampled the Subantarctic Zone (SAZ), the Subantarctic Front (SAF), the Polar Front Zone (PFZ), the Interpolar Front Zone (IPFZ), the southern Antarctic Zone (AZ-S) and the Seasonal Ice Zone (SIZ). More than 90 seawater samples from the whole water column, including silicic acid depleted surface waters, were analysed (Cardinal et al., 2005). Furthermore, for the area between the PFZ to the SIZ we also acquired the isotopic composition of 30 surface size fractionated biogenic Si samples ( > 0.4 μ m, 20-70 μ m and > 70 μ m). No systematic isotopic fractionation was observed related to size fraction, giving con- fidence in the proxy. Biogenic Si, surface, and mesopelagic waters, display a clear latitudinal gradient of isotopic compositions becoming lighter southward of the PFZ. This gradient is much steeper for biogenic Si (0.8 p.mil variation in d29Si) than for silicic acid (0.2 p.mil). In the SAZ, surface and mesopelagic waters do not exhibit a heavier isotopic composition than in the PFZ-IPFZ, in contrast to what was expected from a global modelling study (Wischmeyer et al., 2003). By taking into account these latitudinal changes, and by applying a simple multi-box open system model we esti- mate a fractionation factor, which differs from a previous estimate for the Southern Ocean (Varela et al., 2004), but is well in accordance with the one reported for cul- tured tropical diatoms (De La Rocha et al., 1997). Only the southernmost station in the SIZ behaved differently and it is suspected that release of sea ice diatoms might have disturbed the isotopic signal. Silicic acid isotopic signatures in the deep-water column are generally homogeneous, except at the southernmost station where the imprint of newly formed Antarctic Bot- tom Water, off Adelie Land, is recorded. Overall, our results reflect latitudinal ... |
author2 |
Centre for Energy and Environment (CERI EE - IMT Nord Europe) Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Nord Europe) Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT) |
format |
Conference Object |
author |
Cardinal, D. Alleman, L. Savoye, N. Trull, T. Dehairs, F. André, L. |
author_facet |
Cardinal, D. Alleman, L. Savoye, N. Trull, T. Dehairs, F. André, L. |
author_sort |
Cardinal, D. |
title |
Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? |
title_short |
Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? |
title_full |
Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? |
title_fullStr |
Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? |
title_full_unstemmed |
Using silicon isotopes in oceanography: What can we learn from a high-resolution transect in the Southern Ocean? |
title_sort |
using silicon isotopes in oceanography: what can we learn from a high-resolution transect in the southern ocean? |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.science/hal-04225649 |
op_coverage |
Vienna, Austria |
long_lat |
ENVELOPE(-60.583,-60.583,-62.933,-62.933) |
geographic |
Antarctic Southern Ocean Varela |
geographic_facet |
Antarctic Southern Ocean Varela |
genre |
Adelie Land Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Adelie Land Antarc* Antarctic Sea ice Southern Ocean |
op_source |
Geophysical Research Abstracts, European Geoscience Union https://hal.science/hal-04225649 European Geoscience Union, Apr 2005, Vienna, Austria |
op_relation |
hal-04225649 https://hal.science/hal-04225649 |
_version_ |
1811637097124069376 |