This work will continue innovative investigations into cluster chemistry of hydrometeor systems and what they reveal as to the behavior of gas-to-particle conversion processes, and the nature of atmospheric aerosol particles. Clusters are small gas-phase aggregates of atoms or molecules whose composition and size characteristics can be controlled in a laboratory setting, allowing their reactivity and growth to be studied. Heterogeneous processes in systems applicable to atmospheric chemistry such as nucleation, solvation and surface adsorption are thus amenable to detailed mechanistic investigation. Systems to be studied include: . Dissolution and nucleation processes of water cluster ions and acids . Solvation phenomena in acids and simple salts (e.g., HX where X is a halogen; nitric acid) including halogen replacement, a known atmospheric process . Existence of biradical ions and ion-pair formation in haloacids and other acid systems . Nucleation of organic species (e.g., acetone, pyridine, simple carboxylic acids, halogenated organics and polycyclic aromatic hydrocarbons in water clusters). A broader impact of these investigations is the ongoing dialog between the disciplines of physical chemistry and atmospheric chemistry, including interdisciplinary concept and technique awareness and student training.
