Geochemical iron cycle in the Southern Ocean and its relation to phytoplankton
Sarthou, G.; Jeandel, C. (1996). Geochemical iron cycle in the Southern Ocean and its relation to phytoplankton, in: Baeyens, J. et al. (Ed.) Integrated Marine System Analysis. European Network for Integrated Marine System Analysis. FWO Vlaanderen: minutes of the first network meeting (Brugge, 29.02.96-02.03.96). pp. 36-51
In: Baeyens, J. et al. (Ed.) (1996). Integrated Marine System Analysis. European Network for Integrated Marine System Analysis. FWO Vlaanderen: minutes of the first network meeting (Brugge, 29.02.96-02.03.96). Vrije Universiteit Brussel. Laboratorium voor Analytische Chemie: Brussel. 217 pp., meer
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Documenttype: Congresbijdrage
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| Abstract |
Total dissolvable iron (TDFe), and particulate iron (PFe) measurements were performed in the upper 250 m along a North-South transect in the Austral Ocean (62°00E/66°42S-49°00S, ANTARES II cruise, February 1994). TDFe was organically extracted (APDC/DDDC-Chloroform) and analysed by Graphite Furnace Atomic Absorption Spectrometry (GFAAS), and PFe was analysed by GFAAS following a strong mixed-acid leach. Corresponding detection limits are equal to 0.13 nmol/kg, and 0.02 nmol/kg. TDFe concentrations vary from 0.4 to 6.2 nmol/kg and the profiles are not completly depleted in the surface. PFe concentrations vary from 0.02 to 0.2 nmol/kg. The iron/carbon (Fe/C) uptake ratios for phytoplankton were calculated either from seawater or particle measurements. They are variable along the transect but both consistent when they could be compared. All the observed ratios are within the range of values proposed for the Fe/C uptake ratios by phytoplankton. Using our uptake ratio calculated in the Permanent Open Ocean Zone (4 10-6 mol/mol), we estimate that the primary production which can be supported by the iron input flux into the surface waters is two times higher than the measured primary production in the same area. |
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