Hybrid water adsorption and solubility partitioning for aerosol hygroscopicity and droplet growth

Abstract. In this work, we studied the cloud condensation nuclei (CCN) activity and subsaturated droplet growth of phthalic acid (PTA), isophthalic acid, (IPTA) terephthalic (TPTA), significant benzene polycarboxylic acids structural isomers found in atmosphere. Köhler theory (KT) can be effectively applied for hygroscopicity analysis PTA due to its higher aqueous solubility compared IPTA TPTA. As with other studies partially water-soluble water-insoluble species, supersaturated derived from KT principles do not agree. To address disparities sub- growth, developed a new analytical framework called Hybrid Activity Model (HAM). HAM incorporates solute within an adsorption-based activation framework. Frenkel–Halsey–Hill (FHH) adsorption (FHH-AT) was combined compound develop HAM. Analysis validated using laboratory measurements pure PTA, IPTA, TPTA PTA–IPTA internal mixtures. Furthermore, results generated were tested against traditional FHH-AT compare their water uptake predictive capabilities. A single parameter also based on Results show that HAM-based successfully simulate behavior internally mixed samples. indicate may atmospheric aerosols varying chemical structures solubility.