Our general scientific approach to fulfil the objectives is based on the coupling of : i) physical oceanography ; with ii) the biogeochemistry, including nutritive trace metals (Fe, Co, Zn, Cu, Cd, and probably Mn), in the water-column, the atmosphere and the sediments ; iii) the study of selected trace elements and isotopes, in the water-column and the sediments, that are tracers of lithogenic sources, of circulation, " ageing " and ventilation of water-masses, of biogeochemical processes, and that can be used to quantify the particulate export fluxes from the surface towards the deep waters ; and iv) with the development of modellings that combine large and regional scales, idealized modelling, biogeochemical modelling, and simulations of trace elements and isotopes (Figure 1).

Figure 1- Scientific approach of the BONUS-GOODHOPE project