Box Model Intercomparison of Cloud Chemistry

Chemical processes in clouds and fogs can substantially alter atmospheric oxidant budgets lead to aerosol mass formation. However, many regional global models do not include detailed aqueous-phase chemical mechanisms due the (a) lack of complete understanding (b) computational burden adding constituents. Current gas-aqueous chemistry 0-dimensional were evaluated a cloud-chemistry box model intercomparison based on mid-September 2016 cloud event at Whiteface Mountain, New York. Multiphase five participating ranged from those appropriate for 3-d highly complex with thousands reactions. This study focused levels both phases sulfate organic acid Comparison gas-phase-only gives very similar predictions night but shows significant differences during daytime hydroxyl radical (OH) variability about an order magnitude. The results increases aqueous different Henry's Law constants, reaction rate mechanisms. Using prescribed liquid water content pH value 4.5, modeled OH, aldehyde, concentrations differ by over magnitude daytime. Simulations also conducted = 5.1, predicted variable pH, added transition metal ion chemistry. While we compare measured inorganic anions water-soluble carbon, cannot so measurements. We highlight need recommended equilibrium constants.