The use of survey data to investigate ozone sensitivity to point sources

During the Southern Oxidants Studyʹs 1992 Atlanta Intensive, a survey was conducted to improve the emission estimates from point sources for the Atlanta metropolitan region. The survey consisted of a questionnaire and a daily activity log for the largest point sources in the region. The point source information was used to compare a 1992 typical summer dayʹs emissions with a specific dayʹs emissions (10 August 1992). Both emission inventories indicate that about 90% of point source nitrogen oxides (NOx) emissions were from power plants. Furthermore, our results show that the daily variation of point source NOx emissions during the Intensive Study was mostly due to the emissions from the power plants. The daily variation of NOx emissions with respect to a typical summer day was as much as 24%. Although the day-to-day variability in point source VOC emissions was as much as 28%, their contribution to the total VOC was not significant. Finally, we evaluate the impact of NOx emissions from power plants on ozone concentrations. Air quality model simulations show significantly different ozone concentrations depending on power plant location.