Articles | Volume 9, issue 3
Biogeosciences, 9, 925–940, 2012

Special issue: How changes in ice cover, permafrost and UV radiation impact...

Biogeosciences, 9, 925–940, 2012

Research article 06 Mar 2012

Research article | 06 Mar 2012

Tracing the transport of colored dissolved organic matter in water masses of the Southern Beaufort Sea: relationship with hydrographic characteristics

A. Matsuoka1,2, A. Bricaud1, R. Benner3, J. Para4,5,6, R. Sempéré4,5,6, L. Prieur1, S. Bélanger7, and M. Babin1,2 A. Matsuoka et al.
  • 1Laboratoire d'Océanographie de Villefranche, UMR 7093, Université Pierre et Marie Curie (Paris 6)/Centre National de la Recherche Scientifique (CNRS), B.P. 08, Port de la Darse, Villefranche-sur-Mer Cedex, 06230, France
  • 2Takuvik Joint International Laboratory, Université Laval (Canada) – CNRS (France), Département de Biologie and Québec-Océan, Université Laval, Pavillon Alexandre-Vachon 1045, avenue de la Médecine, Local 2078, G1V 0A6, Canada
  • 3Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
  • 4Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), 13288, Marseille, Cedex 09, France
  • 5Université du Sud Toulon-Var, MIO, 83957, La Garde Cedex, France
  • 6CNRS/INSU, MIO UMR 7294; IRD, MIO UMR 235, France
  • 7Université du Québec à Rimouski, Département de Biologie, Chimie et Géographie, 300 allée des Ursulines, Rimouski, Québec, G5L 3A1, Canada

Abstract. Light absorption by colored dissolved organic matter (CDOM) [aCDOM(λ)] plays an important role in the heat budget of the Arctic Ocean, contributing to the recent decline in sea ice, as well as in biogeochemical processes. We investigated aCDOM(λ) in the Southern Beaufort Sea where a significant amount of CDOM is delivered by the Mackenzie River. In the surface layer, aCDOM(440) showed a strong and negative correlation with salinity, indicating strong river influence and conservative transport in the river plume. Below the mixed layer, a weak but positive correlation between aCDOM(440) and salinity was observed above the upper halocline, resulting from the effect of removal of CDOM due to brine rejection and lateral intrusion of Pacific summer waters into these layers. In contrast, the relationship was negative in the upper and the lower haloclines, suggesting these waters originated from Arctic coastal waters. DOC concentrations in the surface layer were strongly correlated with aCDOM(440) (r2 = 0.97), suggesting that this value can be estimated in this area, using aCDOM(440) that is retrieved using satellite ocean color data. Implications for estimation of DOC concentrations in surface waters using ocean color remote sensing are discussed.

Final-revised paper