The objective is to document and understand the different steps of the life-time of gaseous and particulate species from their emission, transport and chemical evolution to their deposition on the continental surfaces. Wet and dry deposition is the final stage of the biogeochemical cycles of elements having impacts on the oceanic and terrestrial ecosystems. In a context of global changes, the whole geochemical cycles of short-lived atmospheric species must be monitored. Long-term observations are required (1) by the evolution of climatic conditions in Africa and by the strong uncertainties on this evolution and (2) by the increasing anthropogenic pressure and the induced changes in the distribution of the population and in the land-use (cultivation/pasture/biomass burning/pollution from megacities).
To fulfill these objectives, the INDAAF long term monitoring network performs measurements
(1) of the chemical composition of the atmosphere in Africa to document the temporal and spatial evolution of trace gas and aerosol concentrations
(2) of wet and dry atmospheric deposition fluxes using quality controlled measurements at the regional-ecosystem scale.