Keywords: air quality, air pollution, atmospheric dispersion modelling, SOA formation, acidic effect, CMAQ, CHIMERE, SO2, sulphur dioxide, secondary organic aerosol, anthropogenic VOCs, volatile organic compounds, photooxidation, simulation, gas phase chemistry, aerosol formation
SO2 effect on secondary organic aerosol from a mixture of anthropogenic VOCs: experimental and modelled results
The effect of SO2 in the photooxidation of a mixture of anthropogenic precursors is studied. Four experiments are carried out in the EUPHORE outdoor chamber, adding different initial SO2 concentrations in each experiment. The experimental secondary organic aerosol (SOA) obtained in the experiments is compared with the aerosol simulated by two air quality models (CMAQ and CHIMERE) under the same initial conditions. A simplified version of the models is designed in order to consider the closed system of the chamber, where only gas phase chemistry and aerosol formation take place. While the experimental results show a clear increase of the aerosol formed in the presence of increasing SO2 concentrations, the models do not consider this enhancement in the simulations. The behaviour of the models points out the need of a way to implement this effect on anthropogenic secondary organic aerosol.