Sources and transport of dissolved iron and manganese along the continental margin of the Bay of Biscay
|Author(s)||Laes Agathe5, 6, Blain S1, Laan P2, Ussher S3, Achterberg E4, Treguer Paul5, De Baar H. J. W.2|
|Affiliation(s)||1 : Ctr Oceanol Marseille, LOB UMR 6535, CNRS, F-13288 Marseille, France.
2 : Royal Netherlands Inst Sea Res, NIOZ, Texel, Netherlands.
3 : Univ Plymouth, Sch Earth Ocean & Environm Sci, Plymouth PL4 8AA, Devon, England.
4 : Univ Southampton, Natl Oceanog Ctr Southampton, Southampton SO14 3ZH, Hants, England.
5 : Inst Univ Europeen Mer, LEMAR, UMR 6539, CNRS, F-29280 Plouzane, France.
|Source||Biogeosciences (1726-4170) (European Geosciences Union), 2007 , Vol. 4 , P. 181-194|
|WOS© Times Cited||28|
|Abstract||Dissolved iron (DFe; <0.2 mu m) and dissolved manganese (DMn; <0.2 mu m) concentrations were determined in the water column of the Bay of Biscay (eastern North Atlantic Ocean) in March 2002. The samples were collected along a transect traversing from the European continental shelf over the continental slope. The highest DFe and DMn concentrations (2.39 nM and 6.10 nM, respectively) were observed in the bottom waters on the shelf at stations closest to the coast. The release of trace metal from resuspended particles and the diffusion from pore waters were probably at the origin of elevated DFe and DMn concentrations in the Bottom Boundary Layer (BBL). In the slope region, the highest total dissolvable iron (TDFe), DFe and DMn values (24.6 nM, 1.58 nM and 2.12 nM, respectively) were observed close to the bottom at depth of ca. 600-700 m. Internal wave activity and slope circulation are thought to be at the origin of this phenomenon. These processes were also very likely the cause of elevated concentrations (DFe: 1.27 nM, DMn: 2.34 nM) measured in surface waters of stations located in the same area. At stations off the continental slope, the vertical distribution of both metals were typical of open ocean conditions, indicating that inputs from the continental margin did not impact the metal distributions in the offshore waters.|