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Titel |
Iron profiles and speciation of the upper water column at the Bermuda Atlantic Time-series Study site: a model based sensitivity study |
VerfasserIn |
Lisa Weber, C. Völker, A. Oschlies, H. Burchard |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 4, no. 4 ; Nr. 4, no. 4 (2007-08-23), S.689-706 |
Datensatznummer |
250001862
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Publikation (Nr.) |
copernicus.org/bg-4-689-2007.pdf |
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Zusammenfassung |
A one-dimensional model of the biogeochemistry and speciation of iron
is coupled with the General Ocean Turbulence Model (GOTM) and a
NPZD-type ecosystem model.
The model is able to simulate the temporal patterns and vertical
profiles of dissolved iron (dFe) in the upper ocean at the Bermuda Atlantic
Time-series Study site reasonably well.
Subsurface model profiles strongly depend on the parameter values
chosen for the loss processes for iron, colloidal aggregation and
scavenging onto particles.
Estimates for these parameters based on observations in
particle-rich waters result in depletion of dFe.
A high stability constant of iron-binding organic ligands is required
to reproduce the observed degree of organic complexation below the
mixed layer. The scavenging residence time for iron in the
model is shortest in spring and summer, because of the larger
abundance of particles, and increases with depth towards values on the
order of a hundred years.
A solubility of atmospherically deposited iron higher than
2% lead to dFe concentrations incompatible with observations.
Despite neglecting ultraviolet radiation, the model produces diurnal
variations and mean vertical profiles of H2O2 and iron species
that are in good agreement with observations. |
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