Light Hydrocarbon and Oxidant Transport Studies in Ohio - 1974.

摘要

This report describes a field research study carried out in the Canton,Ohio,area during July, 1974. Light hydrocarbons,oxidant and other air pollution parameters were monitored in the city and in the surrounding area both at ground level and aloft using an instrumented light aircraft. Air pollutant concentrations both in the urban center and over the region were shown to have strong dependence on synoptic weather patterns and in particular to the passage of high pressure systems. The pollutant characteristics of the air within a fresh or recent system that had moved out of Canada exhibited relatively low pollutant loads. After the air mass within the system had been present over the Midwest area for three to four days,pollutant burdens including both hydrocarbons and photochemical oxidant were significantly higher. Winds during this period of higher concentrations were typically from the southwest at moderate speeds. Aircraft data showed that pollutants were frequently widespread over the region and present in one or more layers above the ground and through the lowest several thousand feet of the atmosphere. In areas directly downwind of major urban centers,ozone concentrations were inversely correlated with nitrogen oxide levels.