Statistical analyses of meteorological and contaminant data and chemical kinetic modeling demonstrate that (i) the concentrations of ozone in the New Jersey-New York City metropolitan area are regional in character; (ii) ozone concentrations in Connecticut are increased by approximately 20 percent as a consequence of primary emissions in the New Jersey-New York City metropolitan region and subsequent transport; and (iii) the concentrations of a variety of products of smog chemistry in the New Jersey area are markedly increased by an increase in NO emissions, but are minimally affected by a change in hydrocarbon emissions.