The distribution of AI in the IOC stations of the North Atlantic and Norwegian Sea between 52 degrees and 65 degrees North

• Published in: Marine Chemistry
• Main Authors: Hall, Ian Robert, Measures, C. I.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 1998
• Subjects: GC Oceanography; Arctic; Norwegian Sea; Western Basin; Labrador Sea; North Atlantic
• Online Access: https://orca.cardiff.ac.uk/id/eprint/30536/; https://doi.org/10.1016/S0304-4203(98)00008-5

The vertical distribution of dissolved and reactive aluminium was determined at nine stations in the eastern and western North Atlantic, the Norwegian Sea and on a surface water transect during the International Oceanographic Commission's second open ocean baseline survey. The profile results show that the distribution of dissolved Al is primarily the result of advective movement of the various water masses that appear in these stations. Control of the dissolved Al distribution in the central and upper waters of the eastern and western basin of the North Atlantic appears to be related to the mixing series forming these waters. Namely, in the eastern basin by mixing of low salinity, low Al core North Atlantic Central Water (NACW) with high salinity, high Al Mediterranean Water (MW). Dissolved Al concentrations in a series of remnant mixed layers seen immediately above the NACW are consistent with the production of this water mass by deep wintertime convection. In the western basin and Charlie Gibbs Fracture Zone, the influence of the MW is restricted by the invasion of eastward spreading Labrador Sea Water (LSW). The central waters of the western basin primarily reflect a two end-member mixing of core LSW and high salinity moderate to low Al surface waters. Dissolved Al in surface waters along the ship's track range between 0.88 and 3.3 nM and generally reflect the prevailing salinity distribution. We show that the elevated deep water Al concentrations seen in the North Atlantic cannot be supported by either advection of high Al waters from the Arctic seas or by addition of Al from resuspension of bottom material in the high energy overflow zones. We present a mass balance of Al in the North Atlantic. Our calculations show that there is a `missing' flux of some 6.1×109 mol of Al yr−1 entering the North Atlantic Ocean. We examine the potential for the partial dissolution of eolian dust to provide this missing Al and demonstrate that a dissolution of 3% provides a balance within the errors inherent in these ...