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

Continuous measurements of O3, 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 O3 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.