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Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends
Citation
Sedwick, PN and Bowie, AR and Trull, T, Dissolved iron in the Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and seasonal trends, Deep Sea Research Part I: Oceanographic Research Papers, 55, (8) pp. 911-925. ISSN 0967-0637 (2008) [Refereed Article]
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Copyright Statement
The definitive version is available at http://www.sciencedirect.com
Official URL: http://www.sciencedirect.com
DOI: doi:10.1016/j.dsr.2008.03.011
Abstract
We report measurements of dissolved iron (dFe, o0.4 mm) in seawater collected from the
upper 300m of the water column along the CLIVAR SR3 section south of Tasmania in
March 1998 (between 421S and 541S) and November–December 2001 (between 471S and
661S). 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 (o0.1 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 (150m depth) dFe concentrations
in November–December 2001 suggests a net seasonal biological uptake of at least
0.14–0.18 nM dFe, of which 0.05–0.12nM 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 ( 0.03nM) within the Polar Frontal Zone.
Further north, most of our iron profiles do not exhibit near-surface depletions, and mixedlayer
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 timevarying
inputs of aerosol iron or advection of iron-rich subtropical waters from the north.
Item Details
Item Type: | Refereed Article |
---|---|
Keywords: | Iron, Southern Ocean, Antarctic Zone, Sea ice, Polar waters |
Research Division: | Earth Sciences |
Research Group: | Oceanography |
Research Field: | Chemical oceanography |
Objective Division: | Environmental Management |
Objective Group: | Coastal and estuarine systems and management |
Objective Field: | Measurement and assessment of estuarine water quality |
UTAS Author: | Sedwick, PN (Dr Peter Sedwick) |
UTAS Author: | Bowie, AR (Professor Andrew Bowie) |
UTAS Author: | Trull, T (Professor Thomas Trull) |
ID Code: | 54685 |
Year Published: | 2008 |
Web of Science® Times Cited: | 73 |
Deposited By: | IASOS |
Deposited On: | 2009-02-26 |
Last Modified: | 2009-07-27 |
Downloads: | 0 |
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