(Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547
Silicon isotopic signatures (d30Si) of water column silicic acid (Si(OH)4) were measured in the Southern Ocean, along a meridional transect from South Africa (Subtropical Zone) down to 57° S (northern Weddell Gyre). This provides the first reported data of a summer transect across the whole Antarcti...
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Language: | English |
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PANGAEA - Data Publisher for Earth & Environmental Science
2011
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Online Access: | https://dx.doi.org/10.1594/pangaea.809699 https://doi.pangaea.de/10.1594/PANGAEA.809699 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Event label Date/Time of event Latitude of event Longitude of event DEPTH, water Silicic acid δ30Si, silicic acid δ30Si, error Sample comment CTD/Rosette Colorimetry Multi-collector inductively coupled plasma mass spectrometer MC-ICP-MS MD166 Marion Dufresne 1995 Global marine biogeochemical cycles of trace elements and their isotopes GEOTRACES International Polar Year 2007-2008 IPY |
spellingShingle |
Event label Date/Time of event Latitude of event Longitude of event DEPTH, water Silicic acid δ30Si, silicic acid δ30Si, error Sample comment CTD/Rosette Colorimetry Multi-collector inductively coupled plasma mass spectrometer MC-ICP-MS MD166 Marion Dufresne 1995 Global marine biogeochemical cycles of trace elements and their isotopes GEOTRACES International Polar Year 2007-2008 IPY Fripiat, François Cavagna, Anne-Julie Dehairs, Frank Speich, Sabrina André, Luc Cardinal, Damien (Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 |
topic_facet |
Event label Date/Time of event Latitude of event Longitude of event DEPTH, water Silicic acid δ30Si, silicic acid δ30Si, error Sample comment CTD/Rosette Colorimetry Multi-collector inductively coupled plasma mass spectrometer MC-ICP-MS MD166 Marion Dufresne 1995 Global marine biogeochemical cycles of trace elements and their isotopes GEOTRACES International Polar Year 2007-2008 IPY |
description |
Silicon isotopic signatures (d30Si) of water column silicic acid (Si(OH)4) were measured in the Southern Ocean, along a meridional transect from South Africa (Subtropical Zone) down to 57° S (northern Weddell Gyre). This provides the first reported data of a summer transect across the whole Antarctic Circumpolar Current (ACC). d30Si variations are large in the upper 1000 m, reflecting the effect of the silica pump superimposed upon meridional water transfer across the ACC: the transport of Antarctic surface waters northward by a net Ekman drift and their convergence and mixing with warmer upper-ocean Si-depleted waters to the north. Using Si isotopic signatures, we determine different mixing interfaces: the Antarctic Surface Water (AASW), the Antarctic Intermediate Water (AAIW), and thermoclines in the low latitude areas. The residual silicic acid concentrations of end-members control the d30Si alteration of the mixing products and with the exception of AASW, all mixing interfaces have a highly Si-depleted mixed layer end-member. These processes deplete the silicic acid AASW concentration northward, across the different interfaces, without significantly changing the AASW d30Si composition. By comparing our new results with a previous study in the Australian sector we show that during the circumpolar transport of the ACC eastward, the d30Si composition of the silicic acid pools is getting slightly, but significantly lighter from the Atlantic to the Australian sectors. This results either from the dissolution of biogenic silica in the deeper layers and/or from an isopycnal mixing with the deep water masses in the different oceanic basins: North Atlantic Deep Water in the Atlantic, and Indian Ocean deep water in the Indo-Australian sector. This isotopic trend is further transmitted to the subsurface waters, representing mixing interfaces between the surface and deeper layers. Through the use of d30Si constraints, net biogenic silica production (representative of annual export), at the Greenwich Meridian is estimated to be 5.2 ± 1.3 and 1.1 ± 0.3 mol Si/m**2 for the Antarctic Zone and Polar Front Zone, respectively. This is in good agreement with previous estimations. Furthermore, summertime Si-supply into the mixed layer of both zones, via vertical mixing, is estimated to be 1.6 ± 0.4 and 0.1 ± 0.5 mol Si/m**2, respectively. : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 |
format |
Dataset |
author |
Fripiat, François Cavagna, Anne-Julie Dehairs, Frank Speich, Sabrina André, Luc Cardinal, Damien |
author_facet |
Fripiat, François Cavagna, Anne-Julie Dehairs, Frank Speich, Sabrina André, Luc Cardinal, Damien |
author_sort |
Fripiat, François |
title |
(Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 |
title_short |
(Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 |
title_full |
(Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 |
title_fullStr |
(Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 |
title_full_unstemmed |
(Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 |
title_sort |
(table 1) water column silicic acid concentrations and si isotopic composition during marion dufresne cruise md166 off south africa, supplement to: fripiat, françois; cavagna, anne-julie; dehairs, frank; speich, sabrina; andré, luc; cardinal, damien (2011): silicon pool dynamics and biogenic silica export in the southern ocean inferred from si-isotopes. ocean science, 7(5), 533-547 |
publisher |
PANGAEA - Data Publisher for Earth & Environmental Science |
publishDate |
2011 |
url |
https://dx.doi.org/10.1594/pangaea.809699 https://doi.pangaea.de/10.1594/PANGAEA.809699 |
geographic |
Antarctic Southern Ocean The Antarctic Indian Weddell Greenwich |
geographic_facet |
Antarctic Southern Ocean The Antarctic Indian Weddell Greenwich |
genre |
Antarc* Antarctic International Polar Year IPY North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic International Polar Year IPY North Atlantic Deep Water North Atlantic Southern Ocean |
op_relation |
https://dx.doi.org/10.5194/os-7-533-2011 https://dx.doi.org/10.1594/pangaea.809702 |
op_rights |
Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/pangaea.809699 https://doi.org/10.5194/os-7-533-2011 https://doi.org/10.1594/pangaea.809702 |
_version_ |
1766042934820470784 |
spelling |
ftdatacite:10.1594/pangaea.809699 2023-05-15T13:33:30+02:00 (Table 1) Water column silicic acid concentrations and Si isotopic composition during Marion Dufresne cruise MD166 off South Africa, supplement to: Fripiat, François; Cavagna, Anne-Julie; Dehairs, Frank; Speich, Sabrina; André, Luc; Cardinal, Damien (2011): Silicon pool dynamics and biogenic silica export in the Southern Ocean inferred from Si-isotopes. Ocean Science, 7(5), 533-547 Fripiat, François Cavagna, Anne-Julie Dehairs, Frank Speich, Sabrina André, Luc Cardinal, Damien 2011 text/tab-separated-values https://dx.doi.org/10.1594/pangaea.809699 https://doi.pangaea.de/10.1594/PANGAEA.809699 en eng PANGAEA - Data Publisher for Earth & Environmental Science https://dx.doi.org/10.5194/os-7-533-2011 https://dx.doi.org/10.1594/pangaea.809702 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Event label Date/Time of event Latitude of event Longitude of event DEPTH, water Silicic acid δ30Si, silicic acid δ30Si, error Sample comment CTD/Rosette Colorimetry Multi-collector inductively coupled plasma mass spectrometer MC-ICP-MS MD166 Marion Dufresne 1995 Global marine biogeochemical cycles of trace elements and their isotopes GEOTRACES International Polar Year 2007-2008 IPY Supplementary Dataset dataset Dataset 2011 ftdatacite https://doi.org/10.1594/pangaea.809699 https://doi.org/10.5194/os-7-533-2011 https://doi.org/10.1594/pangaea.809702 2022-02-08T16:29:46Z Silicon isotopic signatures (d30Si) of water column silicic acid (Si(OH)4) were measured in the Southern Ocean, along a meridional transect from South Africa (Subtropical Zone) down to 57° S (northern Weddell Gyre). This provides the first reported data of a summer transect across the whole Antarctic Circumpolar Current (ACC). d30Si variations are large in the upper 1000 m, reflecting the effect of the silica pump superimposed upon meridional water transfer across the ACC: the transport of Antarctic surface waters northward by a net Ekman drift and their convergence and mixing with warmer upper-ocean Si-depleted waters to the north. Using Si isotopic signatures, we determine different mixing interfaces: the Antarctic Surface Water (AASW), the Antarctic Intermediate Water (AAIW), and thermoclines in the low latitude areas. The residual silicic acid concentrations of end-members control the d30Si alteration of the mixing products and with the exception of AASW, all mixing interfaces have a highly Si-depleted mixed layer end-member. These processes deplete the silicic acid AASW concentration northward, across the different interfaces, without significantly changing the AASW d30Si composition. By comparing our new results with a previous study in the Australian sector we show that during the circumpolar transport of the ACC eastward, the d30Si composition of the silicic acid pools is getting slightly, but significantly lighter from the Atlantic to the Australian sectors. This results either from the dissolution of biogenic silica in the deeper layers and/or from an isopycnal mixing with the deep water masses in the different oceanic basins: North Atlantic Deep Water in the Atlantic, and Indian Ocean deep water in the Indo-Australian sector. This isotopic trend is further transmitted to the subsurface waters, representing mixing interfaces between the surface and deeper layers. Through the use of d30Si constraints, net biogenic silica production (representative of annual export), at the Greenwich Meridian is estimated to be 5.2 ± 1.3 and 1.1 ± 0.3 mol Si/m**2 for the Antarctic Zone and Polar Front Zone, respectively. This is in good agreement with previous estimations. Furthermore, summertime Si-supply into the mixed layer of both zones, via vertical mixing, is estimated to be 1.6 ± 0.4 and 0.1 ± 0.5 mol Si/m**2, respectively. : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 Dataset Antarc* Antarctic International Polar Year IPY North Atlantic Deep Water North Atlantic Southern Ocean DataCite Metadata Store (German National Library of Science and Technology) Antarctic Southern Ocean The Antarctic Indian Weddell Greenwich |