Biogeochemical Dynamics of Particulate Trace Metals in the South-East Atlantic along the GEOTRACES GA08 Section Cruise

Marine particles play an important role in the marine biogeochemical cycling of Trace Elements and Isotopes (TEIs) and are an essential transport vector for many TEIs in marine systems. They act as sources and sinks to many TEIs via sorption, precipitation/dissolution, or biological incorporation, and are involved in many internal cycling processes. Understanding the marine processes and conditions that influence solid-solution partitioning of TEIs is key to understanding the fate and transport of TEIs in marine systems.

This work examines samples collected during the GEOTRACES Section Cruise GA08, which was carried out in the South East Atlantic from Nov-Dec 2015, and encompassed several primary oceanographic features, including the Benguela upwelling system, oxygen minimum zone and the Congo River plume. Particulate TEI samples were processed by applying a sequential leach and digestion procedure (Berger et al. 2008) to separate the labile particulate fraction from refractory phases. Together with data on the dissolved and total particulate TEI concentrations, labile particulate phases provide valuable information on the processes influencing TEI solid-solution partitioning in different oceanographic regions of the SE Atlantic. This work offers insight into the factors affecting the biogeochemical cycling of TEIs in an under-studied region of the South East Atlantic Ocean, and will compare this region with similar data from other locations in the global ocean.