AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Simulation of Heterogeneous Chemistry of SO2 and NOx on Mineral Dust Particles in Ambient Environments Using CAMx
ZECHEN YU, Myoseon Jang, University of Florida
Abstract Number: 156 Working Group: Urban Aerosols
Abstract The surface of mineral dust particles can act as an import sink for atmospheric tracers (e.g., O3, SO2, and NOx) and photochemically enhance the production of oxygenated compounds. During a typical dust event, the extremely high concentration of airborne mineral dust particles is introduced into atmosphere. These dust particles can undergo long-range transport and impact on urban atmospheric environments. However the effects of mineral dust particles on heterogeneous chemistry of inorganic pollutants, such as SO2 and NOx are not well studied due to the lack of kinetic mechanisms. Using the Atmospheric Mineral Aerosol Reaction (AMAR) model, our research team recently launched to the simulation of heterogeneous photooxidation of SO2 and NOx in the presence of mineral dust particles. The prototype AMAR model was evaluated for the formation of sulfate and nitrate using outdoor smog chamber data under the ambient sunlight. In this work, the AMAR model is extended to regional simulation using the Comprehensive Air Quality Model with Extensions (CAMx) by capturing the heterogeneous formation of sulfate and nitrate during the dust event in urban atmosphere. The simulation results using CAMx-AMAR enable the estimation of the lifetime of inorganic trace gases during the dust event. Furthermore, heterogeneous chemistry of SO2 and NOx impacts on the dust’s hygroscopicity, which influences the indirect effects of dust particles by the modulation of Cloud Condensation Nuclei activities. The change of hygroscopicity of dust particles also impacts on heterogeneous chemistry of other polar inorganic trace gases, such as N2O5 and HONO, as well as the formation of secondary organic aerosols.