Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends
We report measurements of dissolved iron (dFe, <0.4 μm) in seawater collected from the upper 300 m of the water column along the CLIVAR SR3 section south of Tasmania in March 1998 (between 42°S and 54°S) and November–December 2001 (between 47°S and 66°S). Results from both cruises indicate a gene...
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Online Access: | https://eprints.utas.edu.au/7585/ https://eprints.utas.edu.au/7585/1/Sedwick.pdf https://doi.org/10.1016/j.dsr.2008.03.011 |
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ftunivtasmania:oai:eprints.utas.edu.au:7585 2023-05-15T13:36:46+02:00 Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends Sedwick, PN Bowie, AR Trull, TW 2008-08 application/pdf https://eprints.utas.edu.au/7585/ https://eprints.utas.edu.au/7585/1/Sedwick.pdf https://doi.org/10.1016/j.dsr.2008.03.011 en eng https://eprints.utas.edu.au/7585/1/Sedwick.pdf Sedwick, PN, Bowie, AR and Trull, TW 2008 , 'Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends' , Deep-Sea Research I, vol. 55, no. 8 , pp. 911-925 , doi:10.1016/j.dsr.2008.03.011 <http://dx.doi.org/10.1016/j.dsr.2008.03.011>. Iron Southern Ocean Antarctic Zone Sea ice Polar waters Article PeerReviewed 2008 ftunivtasmania https://doi.org/10.1016/j.dsr.2008.03.011 2020-05-30T07:21:22Z We report measurements of dissolved iron (dFe, <0.4 μm) in seawater collected from the upper 300 m of the water column along the CLIVAR SR3 section south of Tasmania in March 1998 (between 42°S and 54°S) and November–December 2001 (between 47°S and 66°S). Results from both cruises indicate a general north-to-south decrease in mixed-layer dFe concentrations, from values as high as 0.76 nM in the Subtropical Front to uniformly low concentrations (<0.1 nM) between the Polar Front and the Antarctic continental shelf. Samples collected from the seasonal sea-ice zone in November–December 2001 provide no evidence of significant dFe inputs from the melting pack ice, which may explain the absence of pronounced ice-edge algal blooms in this sector of the Southern Ocean, as implied by satellite ocean-color images. Our data also allow us to infer changes in the dFe concentration of surface waters during the growing season. South of the Polar Front, a comparison of near-surface with subsurface (150 m depth) dFe concentrations in November–December 2001 suggests a net seasonal biological uptake of at least ~0.14–0.18 nM dFe, of which ~0.05–0.12 nM is depleted early in the growing season (before mid December). A comparison of our spring 2001 and fall 1998 data indicates a barely discernible seasonal depletion of dFe (~0.03 nM) within the Polar Frontal Zone. Further north, most of our iron profiles do not exhibit near-surface depletions, and mixed-layer dFe concentrations are sometimes higher in samples from fall 1998 compared to spring 2001; here, the near-surface dFe distributions appear to be dominated by time-varying inputs of aerosol iron or advection of iron-rich subtropical waters from the north. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean University of Tasmania: UTas ePrints Antarctic Southern Ocean The Antarctic Deep Sea Research Part I: Oceanographic Research Papers 55 8 911 925 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
Iron Southern Ocean Antarctic Zone Sea ice Polar waters |
spellingShingle |
Iron Southern Ocean Antarctic Zone Sea ice Polar waters Sedwick, PN Bowie, AR Trull, TW Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends |
topic_facet |
Iron Southern Ocean Antarctic Zone Sea ice Polar waters |
description |
We report measurements of dissolved iron (dFe, <0.4 μm) in seawater collected from the upper 300 m of the water column along the CLIVAR SR3 section south of Tasmania in March 1998 (between 42°S and 54°S) and November–December 2001 (between 47°S and 66°S). Results from both cruises indicate a general north-to-south decrease in mixed-layer dFe concentrations, from values as high as 0.76 nM in the Subtropical Front to uniformly low concentrations (<0.1 nM) between the Polar Front and the Antarctic continental shelf. Samples collected from the seasonal sea-ice zone in November–December 2001 provide no evidence of significant dFe inputs from the melting pack ice, which may explain the absence of pronounced ice-edge algal blooms in this sector of the Southern Ocean, as implied by satellite ocean-color images. Our data also allow us to infer changes in the dFe concentration of surface waters during the growing season. South of the Polar Front, a comparison of near-surface with subsurface (150 m depth) dFe concentrations in November–December 2001 suggests a net seasonal biological uptake of at least ~0.14–0.18 nM dFe, of which ~0.05–0.12 nM is depleted early in the growing season (before mid December). A comparison of our spring 2001 and fall 1998 data indicates a barely discernible seasonal depletion of dFe (~0.03 nM) within the Polar Frontal Zone. Further north, most of our iron profiles do not exhibit near-surface depletions, and mixed-layer dFe concentrations are sometimes higher in samples from fall 1998 compared to spring 2001; here, the near-surface dFe distributions appear to be dominated by time-varying inputs of aerosol iron or advection of iron-rich subtropical waters from the north. |
format |
Article in Journal/Newspaper |
author |
Sedwick, PN Bowie, AR Trull, TW |
author_facet |
Sedwick, PN Bowie, AR Trull, TW |
author_sort |
Sedwick, PN |
title |
Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends |
title_short |
Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends |
title_full |
Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends |
title_fullStr |
Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends |
title_full_unstemmed |
Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends |
title_sort |
dissolved iron in the australian sector of the southern ocean (clivar sr3 section): meridional and seasonal trends |
publishDate |
2008 |
url |
https://eprints.utas.edu.au/7585/ https://eprints.utas.edu.au/7585/1/Sedwick.pdf https://doi.org/10.1016/j.dsr.2008.03.011 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_relation |
https://eprints.utas.edu.au/7585/1/Sedwick.pdf Sedwick, PN, Bowie, AR and Trull, TW 2008 , 'Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends' , Deep-Sea Research I, vol. 55, no. 8 , pp. 911-925 , doi:10.1016/j.dsr.2008.03.011 <http://dx.doi.org/10.1016/j.dsr.2008.03.011>. |
op_doi |
https://doi.org/10.1016/j.dsr.2008.03.011 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
55 |
container_issue |
8 |
container_start_page |
911 |
op_container_end_page |
925 |
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