Modeling SOA formation from the oxidation anthropogenic precursors in an outdoor chamber
Résumé
Secondary organic aerosols (SOA) constitute a significant fraction of the atmospheric particulate matter. These particles are formed as a consequence of the oxidation reaction of certain organic gases that leads to the formation of low-volatility compounds. Much research has been done during the last years to take into account the influence of conditions (like low-NOx or high NOx conditions, dry or humid conditions) in SOA mechanisms. In this study we present a comparison between box model results of a SOA model to measurements done in the outdoor chambers EUPHORE (Ceam, Valencia, Spain; Vivanco et al., 2013). The experiments were focused on a mixture of four anthropogenic VOCs (toluene, 1,3,5 trimethylbenzene, o-xylene and octane) over different sets of conditions (dry or humid conditions, different NOx concentrations and with or without SO2). Some measurements (like measured concentrations of some compounds, SMPS data) were used to constrain the box model and represent properly the gas-phase chemistry, which can impact strongly SOA formation.