A Short-Term Air Quality Model for Sulfur Dioxide in Louisville, Kentucky

Abstract

The conventional gaussian plume equation for ground level concentrations was used to estimate hourly average sulfur dioxide concentrations at selected points in Louisville, KY, on specific days during 1973. Area emission sources were not included in the model since they are not substantial. The trajectory of the emissions from each continuous point source was calculated by a procedure that allowed for spatial variability in wind direction. All other meteorological parameters were held constant during each hour. The twenty-four individual hourly estimates at each location for a given day were arithmetically averaged yielding a daily mean. The model predictions were compared to actual measurements conducted by Jefferson County Air Pollution Control District personnel using the West-Gaeke sampling procedure. The sample correlation coefficient for all predictions was low, but after only about 30 percent of the predictions were eliminated on statistical grounds, the sample correlation coefficient was increased to 0.72. The statistical analysis appeared to discard a reasonable number of predictions on the basis of observed variability in the measured air quality.