Modeling Salt Concentration Effects on Glyoxal/Ammonium Sulfate Dark Chemistry Kinetics

Aerosols have a significant impact on the unsteady-state energy balance of the atmosphere, contributing both warming and cooling effects to global radiative forcing. Light-absorbing brown carbon compounds are formed from reactions of carbonyl-containing volatile organic compounds (CVOCs) such as glyoxal and methylglyoxal which are present in the atmosphere. This research aims to determine if there is a salt concentration dependence on modeled rate constants for the glyoxal/ammonium sulfate dark chemistry reaction system. Experiments are carried out to simulate the glyoxal/ammonium sulfate dark chemistry reaction at different salt (ammonium sulfate) concentrations. The data was compared to the Triple Gaussian model developed in previous studies and rate constants for the system were inferred assuming first order kinetics. Statistical analysis was carried out to determine if the rate constants scale with respect to salt concentrations. The information obtained could provide insight into organic aerosol behavior by furthering our understanding of the influence of salt concentration on rate constants for reactions occurring in the atmosphere.