Aluminium in the North Atlantic Ocean and the Labrador Sea (GEOTRACES GA01 section): roles of continental inputs and biogenic particle removal
|Author(s)||Barraqueta Jan-Lukas Menzel1, Schlosser Christian1, Planquette Helene2, Gourain Arthur2, 3, Cheize Marie2, Boutorh Julia2, Shelley Rachel2, 4, 5, Pereira Leonardo Contreira6, Gledhill Martha1, Hopwood Mark J.1, Lacan Francois7, Lherminier Pascale8, Sarthou Geraldine2, Achterberg Eric P.1|
|Affiliation(s)||1 : Helmholtz Ctr Ocean Res Kid, GEOMAR, Kiel, Germany.
2 : LEMAR, UMR 6539, Plouzane, France.
3 : Univ Liverpool, Sch Environm Sci, Earth Ocean & Ecol Sci, Liverpool, Merseyside, England.
4 : Florida State Univ, Earth Ocean & Atmospher Sci, Tallahassee, FL USA.
5 : Univ Plymouth, Geog Earth & Environm Sci, Plymouth, Devon, England.
6 : Univ Fed Rio Grande FURG, Rio Grande, Brazil.
7 : Univ Toulouse, LEGOS, Toulouse, France.
8 : IFREMER, LOPS, IUEM, Plouzane, France.
|Source||Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2018-08 , Vol. 15 , N. 16 , P. 5271-5286|
|WOS© Times Cited||14|
|Note||Special issue GEOVIDE, an international GEOTRACES study along the OVIDE section in the North Atlantic and in the Labrador Sea (GA01) Editor(s): G. Henderson, M. Lohan, L. Bopp, C. Jeandel, and G. Reverdin|
The distribution of dissolved aluminium (dAl) in the water column of the North Atlantic and Labrador Sea was studied along GEOTRACES section GA01 to unravel the sources and sinks of this element. Surface water dAl concentrations were low (median of 2.5 nM) due to low aerosol deposition and removal by phytoplankton. However, surface water dAl concentrations were enhanced on the Iberian and Greenland shelves (up to 30.9 nM) due to continental inputs (rivers, glacial flour and ice melt). A negative correlation was observed between dAl in surface waters and primary production, phytoplankton community structure and biogenic opal production. The abundance of diatoms exerted a significant (p < 0.01) control on the surface particulate Al (pAl) to dAl ratios by decreasing dAl levels and increasing pAl levels. Dissolved Al concentrations generally increased with depth and correlated strongly with silicate (R2 > 0.76) west of the Iberian Basin, suggesting net release of dAl at depth during remineralization of sinking biogenic opal containing particles. Enrichment of dAl at near-bottom depths was observed due to resuspension of sediments near the sediment-water interface. The highest dAl (up to 38.7 nM) concentrations were observed in Mediterranean Overflow Waters which act as a major source of dAl to mid depth waters of the eastern North Atlantic. This study clearly shows that the vertical and lateral distribution of dAl in the North Atlantic differs when compared to other regions of the North Atlantic and global ocean due to the large spatial differences both in the main source of Al, atmospheric deposition, and the main sink for Al, particle scavenging, between different oceanic regions.