9523124 Donat This study will examine the influence of various inputs on the complexation and speciation of copper and iron, and the concentrations and complexation constants of their complexing ligands in the western Atlantic. The work will also determine the vertical and horizontal distribution of dissolved platinum in these waters, to help elucidate its "true" distribution. This research is performed on the third Intergovernmental Oceanographic Commission (IOC) Baseline Expedition for Trace Metals and Organic Contaminants in the western South and equatorial Atlantic, for 1996. The cruise track provides opportunities to collect samples from a detailed surface water transect across the western boundary currents in the South Atlantic, the Amazon plume (high levels of suspended sediment, terrestrial organic ligands, and colloidal matter), the ITCZ (high wet deposition of Saharan dust), and the equatorial Atlantic upwelling zone (low levels of organic ligands?). The study is consistent uith the goal of the IOC expeditions which is to characterize the major water masses of the world's oceans for as many contaminants as possible to allow future changes in anthropogenic activities to be identified.
