Temporal Changes in trace metal concentrations during an artificial dust deposition to Large Mesocosms (DUNE-2 Experiment)

Abstract

The deposition of atmospheric dust is one of the main external source to the ocean for elements abundant in crustal rocks. Once deposited the residence time of these elements in surface waters differs according to their chemical speciation and biological ultilization. In the present work we examined the temporal changes in the concentrations of Iron, Maganese and Aluminium within large mesocosms after the seeding with simulated aeolian dust of surface waters of the northwestern Mediterranean. Two artificial deposition events were performed during the course of this experiment: for each artificial Saharan dust fertilization to the mesocoms the changes in Mn, Fe and Al chemistry were followed over the following week. In this presentation, we will present results from this mesocosm experiment focusing on the similarities and differences between these 3 elements. This trace metal dataset makes a significant contribution to enhance our knowledge about the release of trace metals from Saharan dust in a low nutrient low chlorophyll area and the subsequent processes of biouptake and scavenging