The Effect of Particle Composition and Concentration on the Partitioning Coefficient for Mercury in Three Ocean Basins

The downward flux of sinking particles is a prominent Hg removal and redistribution process in the ocean; however, it not well-constrained. Using data from three U.S. GEOTRACES cruises including Pacific, Atlantic, Arctic Oceans, we examined mercury partitioning coefficient, K d , water column. suggest that varies widely over ocean basins. We also investigated effect particle concentration composition on by comparing small-sized (1–51 ?m) suspended particulate mass (SPM) as well its compositional fractions six different phases to coefficient. observed an inverse relationship between mass, has been for other metals known “particle effect,” explains much variation . Particulate organic matter (POM) calcium carbonate (CaCO 3 ) dominated all basins while Fe Mn could make difference some places where their concentrations are elevated, such hydrothermal plumes. Finally, our estimated residence time strong negative correlation with average log bulk indicating significant time.