Woods Hole Oceanographic Institution

Phoebe J Lam

»Inverse methods for particle dynamics
»The speciation of marine particulate iron
»The dynamic biological pump
»The continental margin is a key source of iron
»High Biomass Low Export regimes in the Southern Ocean
»Wintertime phytoplankton bloom in the Subarctic Pacific supported by continental margin iron
»Differential effects of iron additions on organic and inorganic carbon production by phytoplankton


Phoebe J. Lam and James K. B. Bishop


The continental margin is a key source of iron to the HNLC North Pacific Ocean

, Geophysical Research Letters, 35, L07608, doi:10.1029/2008GL033294., published 9 April 2008

Here we show that labile particulate iron and manganese concentrations in the upper 500 m of the Western Subarctic Pacific, an iron-limited High Nutrient Low Chlorophyll (HNLC) region, have prominent subsurface maxima between 100 – 200 m, reaching 3 nM and 600 pM, respectively. The subsurface concentration maxima in particulate Fe are characterized by a more reduced oxidation state, suggesting a source from primary volcagenic minerals such as from the Kuril/Kamchatka margin. The systematics of these profiles suggest a consistently strong lateral advection of labile Mn and Fe from redox-mobilized labile sources at the continental shelf supplemented by a more variable source of Fe from the upper continental slope. This subsurface supply of iron from the continental margin is shallow enough to be accessible to the surface through winter upwelling and vertical mixing, and is likely a key source of bioavailable Fe to the HNLC North Pacific.

FILE » LamBishop08GRLmarginFeWSP_102684.pdf

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