Atmospheric deposition fluxes over the Atlantic Ocean: a GEOTRACES case study

Type Article
Date 2019-04
Language English
Author(s) Menzel Barraqueta Jan-Lukas1, 2, Klar Jessica K.3, 4, Gledhill Martha1, Schlosser Christian1, Shelley Rachel5, 6, 7, Planquette Helene6, Wenzel Bernhard1, Sarthou Geraldine6, Achterberg Eric P.1
Affiliation(s) 1 : Helmholtz Ctr Ocean Res Kiel, GEOMAR, Kiel, Germany.
2 : Stellenbosch Univ, Dept Earth Sci, ZA-7600 Stellenbosch, South Africa.
3 : Univ Southampton, Natl Oceanog Ctr, Ocean & Earth Sci, European Way, Southampton SO14 3ZH, Hants, England.
4 : Univ Toulouse, CNRS, CNES, LEGOS,IRD,UPS, 14 Ave Edouard Belin, F-31400 Toulouse, France.
5 : Florida State Univ, Dept Earth Ocean & Atmospher Sci, 117 N Woodward Ave, Tallahassee, FL 32301 USA.
6 : Inst Univ Europeen Mer, CNRS, IFREMER, Lab Sci Environm Marin,LEMAR,UBO,IRD,UMR 6539, Technopole Brest Iroise, F-29280 Plouzane, France.
7 : Univ Plymouth, Sch Geog Earth & Environm Sci, Plymouth PL4 8AA, Devon, England.
Source Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2019-04 , Vol. 16 , N. 7 , P. 1525-1542
DOI 10.5194/bg-16-1525-2019
WOS© Times Cited 25
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, C. Jeandel, M. Lohan, G. Reverdin, and L. Bopp
Abstract

Atmospheric deposition is an important source of micronutrients to the ocean, but atmospheric deposition fluxes remain poorly constrained in most ocean regions due to the limited number of field observations of wet and dry atmospheric inputs. Here we present the distribution of dissolved aluminium (dAl), as a tracer of atmospheric inputs, in surface waters of the Atlantic Ocean along GEOTRACES sections GA01, GA06, GA08, and GA10. We used the surface mixed-layer concentrations of dAl to calculate atmospheric deposition fluxes using a simple steady state model. We have optimized the Al fractional aerosol solubility, the dAl residence time within the surface mixed layer and the depth of the surface mixed layer for each separate cruise to calculate the atmospheric deposition fluxes. We calculated the lowest deposition fluxes of 0.15 +/- 0.1 and 0.27 +/- 0.13 gm(-2) yr(-1) for the South and North Atlantic Ocean (>40 degrees S and > 40 degrees N) respectively, and the highest fluxes of 1.8 and 3.09 gm(-2) yr(-1) for the south-east Atlantic and tropical Atlantic Ocean, respectively. Overall, our estimations are comparable to atmospheric dust deposition model estimates and reported field-based atmospheric deposition estimates. We note that our estimates diverge from atmospheric dust de-position model flux estimates in regions influenced by riverine Al inputs and in upwelling regions. As dAl is a key trace element in the GEOTRACES programme, the approach presented in this study allows calculations of atmospheric deposition fluxes at high spatial resolution for remote ocean regions.

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How to cite 

Menzel Barraqueta Jan-Lukas, Klar Jessica K., Gledhill Martha, Schlosser Christian, Shelley Rachel, Planquette Helene, Wenzel Bernhard, Sarthou Geraldine, Achterberg Eric P. (2019). Atmospheric deposition fluxes over the Atlantic Ocean: a GEOTRACES case study. Biogeosciences, 16(7), 1525-1542. Publisher's official version : https://doi.org/10.5194/bg-16-1525-2019 , Open Access version : https://archimer.ifremer.fr/doc/00491/60227/