Impacts of simulated stability on simulated PM2.5 concentrations

Recently, the Environmental Protection Agency (EPA) tightened the previous National Ambient Air Quality 24-hour standard for particulate matter with aerodynamic diameter <2.5&mu m (PM_2.5) to 35&mu g/m³. Since the observational data collected in the Fairbanks area indicated that PM_2.5 concentrations exceeded the new standard periodically during the past years, a PM_2.5 nonattainment area was assigned. An Alaska-optimized version of WRF/Chem is run for winter 2008/09. Results of the simulation using different parameterizations of the atmospheric boundary layer and surface layer processes will be presented and the impact of simulated stability on simulated PM_2.5 concentrations will be discussed. We will evaluate the model performance with available meteorological and PM_2.5 measurements.