|Abstract Title:||Improving Simulation of Redox Chemistry and Gas Particle Partitioning of Atmospheric Mercury|
|Presenter Name:||Lin Wu|
|Session:||Special Session - New developments in understanding reactive mercury concentrations and chemistry|
Abstract Information :
It has been a daunting task to reproduce the concentrations of reactive mercury (RM=gaseous oxidized mercury (GOM) + particulate borne mercury (PBM)) using chemical transport models due in large part to poor representation of the redox chemistry and gas particle partitioning processes. Most three-dimensional chemical transport models neglect the gas particle partitioning process of speciated GOM. We further improved our mercury chemistry mechanism (CMAQ-newHg-Br) by implementing an improved gas particle partitioning scheme as well as updating the Hg chemical mechanism. Using the modified model with global model output as initial and boundary conditions, we conducted simulations over the northeastern United States for the time period of March-November 2010. The modified model was evaluated through comparison of simulated and observed concentrations and deposition fluxes of gaseous elemental mercury (GEM), GOM, and PBM. The effects of the updated mercury chemistry mechanism and the gas particle partitioning scheme were examined and quantified for spatiotemporal variations in concentrations and deposition of mercury in various environments.