Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps
The Southern Ocean plays a pivotal role in the control of atmospheric CO 2 levels, via both physical and biological sequestration processes. The biological carbon transfer to the ocean interior is tightly coupled to the availability of other elements, especially iron as a trace-limiting nutrient and...
Published in: | Global Biogeochemical Cycles |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley-Blackwell Publishing, Inc.
2015
|
Subjects: | |
Online Access: | https://doi.org/10.1002/2015GB005180 http://ecite.utas.edu.au/106060 |
id |
ftunivtasecite:oai:ecite.utas.edu.au:106060 |
---|---|
record_format |
openpolar |
spelling |
ftunivtasecite:oai:ecite.utas.edu.au:106060 2023-05-15T14:03:26+02:00 Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps Closset, I Cardinal, D Bray, SG Thil, F Djouraev, I Rigual-Hernandez, AS Trull, TW 2015 application/pdf https://doi.org/10.1002/2015GB005180 http://ecite.utas.edu.au/106060 en eng Wiley-Blackwell Publishing, Inc. http://ecite.utas.edu.au/106060/1/Closset_et_al-2015-Global_Biogeochemical_Cycles.pdf http://dx.doi.org/10.1002/2015GB005180 Closset, I and Cardinal, D and Bray, SG and Thil, F and Djouraev, I and Rigual-Hernandez, AS and Trull, TW, Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps, Global Biogeochemical Cycles, 29, (9) pp. 1495-1510. ISSN 0886-6236 (2015) [Refereed Article] http://ecite.utas.edu.au/106060 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2015 ftunivtasecite https://doi.org/10.1002/2015GB005180 2019-12-13T22:07:13Z The Southern Ocean plays a pivotal role in the control of atmospheric CO 2 levels, via both physical and biological sequestration processes. The biological carbon transfer to the ocean interior is tightly coupled to the availability of other elements, especially iron as a trace-limiting nutrient and dissolved silicon as the mineral substrate that allows diatoms to dominate primary production. Importantly, variations in the silicon cycling are large but not well understood. Here we use δ 30 Si measurements to track seasonal flows of silica to the deep sea, as captured by sediment trap time series, for the three major zones (Antarctic, AZ; Polar Frontal, PFZ; and Sub-Antarctic, SAZ) of the open Southern Ocean. Variations in the exported flux of biogenic silica (BSi) and its δ 30 Si composition reveal a range of insights, including that (i) the sinking rate of BSi exceeds 200 m d −1 in summer in the AZ yet decreases to very low values in winter that allow particles to remain in the water column through to the following spring, (ii) occasional vertical mixing events affect the δ 30 Si composition of exported BSi in both the SAZ and AZ, and (iii) the δ 30 Si signature of diatoms is well conserved through the water column despite strong BSi and particulate organic carbon (POC) attenuation at depth and is closely linked to the Si consumption in surface waters. With the strong coupling observed between BSi and POC fluxes in PFZ and AZ, these data provide new constraints for application to biogeochemical models of seasonal controls on production and export. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean eCite UTAS (University of Tasmania) Antarctic Southern Ocean Global Biogeochemical Cycles 29 9 1495 1510 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical Oceanography Closset, I Cardinal, D Bray, SG Thil, F Djouraev, I Rigual-Hernandez, AS Trull, TW Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
The Southern Ocean plays a pivotal role in the control of atmospheric CO 2 levels, via both physical and biological sequestration processes. The biological carbon transfer to the ocean interior is tightly coupled to the availability of other elements, especially iron as a trace-limiting nutrient and dissolved silicon as the mineral substrate that allows diatoms to dominate primary production. Importantly, variations in the silicon cycling are large but not well understood. Here we use δ 30 Si measurements to track seasonal flows of silica to the deep sea, as captured by sediment trap time series, for the three major zones (Antarctic, AZ; Polar Frontal, PFZ; and Sub-Antarctic, SAZ) of the open Southern Ocean. Variations in the exported flux of biogenic silica (BSi) and its δ 30 Si composition reveal a range of insights, including that (i) the sinking rate of BSi exceeds 200 m d −1 in summer in the AZ yet decreases to very low values in winter that allow particles to remain in the water column through to the following spring, (ii) occasional vertical mixing events affect the δ 30 Si composition of exported BSi in both the SAZ and AZ, and (iii) the δ 30 Si signature of diatoms is well conserved through the water column despite strong BSi and particulate organic carbon (POC) attenuation at depth and is closely linked to the Si consumption in surface waters. With the strong coupling observed between BSi and POC fluxes in PFZ and AZ, these data provide new constraints for application to biogeochemical models of seasonal controls on production and export. |
format |
Article in Journal/Newspaper |
author |
Closset, I Cardinal, D Bray, SG Thil, F Djouraev, I Rigual-Hernandez, AS Trull, TW |
author_facet |
Closset, I Cardinal, D Bray, SG Thil, F Djouraev, I Rigual-Hernandez, AS Trull, TW |
author_sort |
Closset, I |
title |
Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps |
title_short |
Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps |
title_full |
Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps |
title_fullStr |
Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps |
title_full_unstemmed |
Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps |
title_sort |
seasonal variations, origin, and fate of settling diatoms in the southern ocean tracked by silicon isotope records in deep sediment traps |
publisher |
Wiley-Blackwell Publishing, Inc. |
publishDate |
2015 |
url |
https://doi.org/10.1002/2015GB005180 http://ecite.utas.edu.au/106060 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
http://ecite.utas.edu.au/106060/1/Closset_et_al-2015-Global_Biogeochemical_Cycles.pdf http://dx.doi.org/10.1002/2015GB005180 Closset, I and Cardinal, D and Bray, SG and Thil, F and Djouraev, I and Rigual-Hernandez, AS and Trull, TW, Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps, Global Biogeochemical Cycles, 29, (9) pp. 1495-1510. ISSN 0886-6236 (2015) [Refereed Article] http://ecite.utas.edu.au/106060 |
op_doi |
https://doi.org/10.1002/2015GB005180 |
container_title |
Global Biogeochemical Cycles |
container_volume |
29 |
container_issue |
9 |
container_start_page |
1495 |
op_container_end_page |
1510 |
_version_ |
1766274079406424064 |