Trace gas concentrations and emissions in downtown Nashville during the 1995 Southern Oxidants Study Nashville intensive

Continuous measurements of O-3, CO, NOy, and SO2 and twice a day samples of hydrocarbons were made over a 40 day period in June and July 1995 at the downtown Nashville Southern Oxidants Study (SOS) site located on the rooftop of the polk office building, 106 m above ground level, in the urban center. This site experiences elevated concentrations of VOCs, CO, and NOy, due to local emissions from the Nashville urban area. High O-3 concentrations were also observed and are discussed with reference to violations of the existing air quality standard and the much harder task of meeting the proposed 8 hour average standard. A comparison between the VOC measurements made from the Department of Energy G-1 aircraft with those measured downtown indicates a preferential loss of reactive ingredients in the samples taken outside of the city. The concentration ratios, VOC/CO (ppbC/ppb), VOC/NOx (ppbC/ppb), and CO/NOx (ppb/ppb) were calculated to be 0.32, 2.9, and 9.3, respectively, from morning samples. These ratios agree to within 35% with estimates from Nashville emissions.