Aerial Investigation of the Ozone Plume Phenomenon

Abstract

Aerial ozone measurements were obtained during the summer of 1975 in the Northeastern United States. This paper reports on the results of a series of tests conducted upwind and downwind of several major metropolitan and industrial complexes, which include Phila-delphia-Camden-Wilmington and New York City-Northeastern New Jersey-Southeastern Connecticut. Flight patterns consisted of upwind and downwind tranverses perpendicular to the urban plume and vertical profiles. The results indicate significant O₃ generation occurs in the urban plumes, but at no time was the difference between the upwind and downwind O₃ concentrations greater than 0.08 ppm (maximum 0.078 ppm). However, in several cases when the upwind values were added to the O₃ produced by the urban area, this was sufficient to result in violations of the NAAQS downwind. The paper also discusses the results of flights over refineries and petrochemical facilities which yielded a positive contribution to downwind O₃ values.