The distribution of oxidized nitrogen in urban air

This paper describes the distribution of oxidized nitrogen compounds in urban air. The studies reported here have focused on NO, NO2, PAN and NO-3. These species have been monitored for periods of several weeks at a nmber of locations throughout the U.S.A. Oxidized nitrogen distribution is discussed in terms of the daily patterns of nitrogen pollutant concentrations, the fractional conversion of NOx to products and the diurnal profile of the conversion fraction, and lastly, the contribution of the individual compounds to the overall oxidized nitrogen burden. Site to site variations in the distribution are explained by photochemical conversion, distance between the site and the source region, and the proximity of local NOx emission sources.