This axe aims to study the aging of the volcanic plume during its regional dispersion regime, where the transport of volcanic pollutants is driven by the environmental wind fields. The focus is to study the formation of secondary aerosol from gaseous precursors, including SO2 and halogens.
Objectives are :
i) to document the chemical transformation of SO2 and halogens into aerosols,
ii) to assess the impact of the presence of an aqueous phase on the physio-chemical properties of the volcanic cloud and its evolution with time,
iii) to document rapid evolution of aerosol number and mass size distributions within a few 10s km (and time scales of less than a minute to hours) of the emission source.
On a local scale the objectives are to quantify the source emission fluxes and to model the distribution, deposition and the composition of the volcanic plume which can cause serious impacts on environment and human health.
On a global scale, the objectives are to improve the knowledge of the contribution of nucleation of volcanic precursors and cloud processing when it occurs to the global particulate burden that may impact climate though their direct and indirect effects.