UNIPAR model

Our laboratory’s recent research efforts have improved the state-of-the science-art via the development of the UNIfied Partitioning-Aerosol phase Reaction model (UNIPAR), which utilizes explicit gas chemistry to predict SOA formation from multiphase reactions. UNIPAR vastly improved the accuracy of chamber generated SOA mass predictions. For example, the UNIPAR prediction of isoprene SOA in the presence of inorganic salted wet aerosol is 3-7 times greater than the SOA mass predicted by partitioning alone, suggesting the importance of in-particle chemistry in SOA growth.

UNIPAR captures the influence of NO_x on SOA formation via modulation of the volatility-reactivity distribution of oxidized products derived from the representation of near-explicit gas mechanisms. UNIPAR comprehensively predicts the SOA mass (OM_T) by incorporating multiphase partitioning (OM_P) of SVOCs between gas, in, and or phases and by representing aerosol chemistry (oligomerization, acid-catalyzed reactions, and OS formation) (OM_AR) of all known SVOC under broad ranges of aerosol acidity and humidity to form both the dry and the wet inorganic salt aerosols. Thus, UNIPAR will improve the accuracy of SOA mass predictions, which are under predicted by current regional models.