Affiliation:
1. GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany
2. Department of Ocean Science and Engineering Southern University of Science and Technology Shenzhen China
3. Now at Federal Institute of Hydrology Koblenz Germany
Abstract
AbstractThe Congo River supplies vast quantities of trace metals (TMs) to the South Atlantic Ocean, but TM budgets for the Congo plume derived using radium isotopes for GEOTRACES cruise GA08 suggest additional input other than the river outflow. Considering the tight correlations between most dissolved TMs and salinity in the plume and the high rainfall during the wet season over the Congo shelf, we hypothesized that wet atmospheric deposition is a TM source to the Congo plume. Observed TM concentrations in rainwaters across the Congo shelf were mostly comparable to values from previous work in the North Atlantic and Mediterranean Sea. Wet deposition contributed the equivalent of 43% dCd, 21% dCu, 20% dPb and 68% dZn of the Congo River fluxes. Our findings show an important role of wet deposition in supplying TMs to the South Atlantic overlapping with the region that receives substantial TM fluxes from the Congo River.
Funder
Deutsche Forschungsgemeinschaft
GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
Publisher
American Geophysical Union (AGU)
Subject
General Earth and Planetary Sciences,Geophysics