Effects of Hypothetical NO_x Sources in East Tennessee on the Ozone Concentrations Impacting the GSMNP

This thesis studied the effects of hypothetical NO_x sources located in East Tennessee on the ozone concentrations impacting the Great Smoky Mountains National Park (GSMNP). The product of this study is a technique of assessing the potential impact of a new or modified large NO_x source on ozone concentrations within a Class I area, without requiring an up-to-date detailed emissions inventory. The study evaluates the MAP-03 model as a screening tool for selecting the day to be modeled by the Urban Airshed Model (UAM) for each hypothetical source location. The four source locations selected to be studied in East Tennessee were: Chattanooga, Crossville, Knoxville, and the Tri-Cities area. The results of MAP-03 simulations were compared to UAM simulation results in determining that the MAP-03 model was effective in selecting the modeling scenarios for which the UAM would predict incremental increases of ozone in the GSMNP due to the potential source. The study also investigates the effects of using EPA default concentrations along the boundary of the modeling domain on predicted ozone concentrations within the modeling domain. It was found that the use of default boundary conditions may significantly affect ozone concentration predictions in the domain, so a technique was developed to minimize these effects by utilizing temporally varying concentrations along the boundary that were predicted during modeling scenarios.