Determining the Role of Acidity, Fate and Formation of IEPOX-Derived SOA in CMAQ

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability species such as sulfate and nitrate, through them, acidity (pH). To elucidate role that play in regulating Secondary Organic Aerosol (SOA), we utilize 2013 Southern Oxidant Study (SOAS) dataset to enhance extensive mechanism isoprene epoxydiol (IEPOX)-mediated SOA formation implemented Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used investigate impact potential future emission controls IEPOX OA. We found Henry’s law coefficient for most impactful parameter aqueous OA products, a value 1.9 × 107 M atm−1 provides best agreement with measurements. Non-volatile cations (NVCs) were higher-than-expected quantities CMAQ exerted significant influence by reducing its production much 30% when present. Consistent previous literature, strong correlation sulfate, little or liquid water content, found. Future reductions SO2 are not affect this generally act increase sensitivity even extreme cases.