RELATIONSHIPS BETWEEN REGIONAL OZONE POLLUTION AND EMISSIONS OF NITROGEN-OXIDES IN THE EASTERN UNITED-STATES

This study examines the relationships between regional ozone (O-3) pol lution and emissions of nitrogen oxides (NOx) in the eastern United St ates during summer. Using measurements from rural sites during the sum mer of 1995, three 4-day time periods are identified during which sign ificant enhancements of surface O-3 occurred on spatial scales ranging from 0.5 to 1.8 million km(2). Each of these episodes was characteriz ed by relatively stagnant meteorological conditions conducive to the p hotochemical formation and accumulation of O-3 in the boundary layer. The surface ozone accumulation efficiency (SOAE), a parameter which re lates the O-3 accumulation to the NOx emission density in a given regi on, is estimated to range from 1 to 2 ppbv O-3 kg(-1) N km(-2) in the eastern United States during summer, This result is discussed in the c ontext of regional NOx-based O-3 control strategies. In addition, the net ozone production efficiency (OPE) is estimated to range from 2 to 3 ppbv O-3 ppbv(-1) NOx in this region.