(92a) Summertime Reactivity of Atmospheric Organic Species in Athens, Ohio

Ozone (O3) exists in a balance with NOx (primarily NO2 and NO) gases in the troposphere. However, organic compounds can disrupt this balance by reacting with the hydroxyl radical (OH) to produce more ozone. This ozone is a major component of atmospheric smog. Organic compounds are divided into two types: anthropogenic, resulting from human actions, and biogenic, produced in natural processes. This study uses the reactivity of several organic compounds with OH to determine the anthropogenic and biogenic contribution to the production of ozone during May, June, and July in Athens, Ohio. Samples were taken at two sites: one affected by activity in Athens and one affected by regional activity. During these months, anthropogenic compounds make up 82 percent of the compounds studied. However, these compounds only contribute 23 percent of the OH reactivity. Studying each month individually shows an increase in reactivity over the summer, due to the increase in biogenic activity. These results illustrate the large impact of biogenic compounds on ozone production during the summer months. The data do not indicate a significant difference in the fraction of OH reactivity due to anthropogenic compounds at the ?Athens? versus the ?regional? site. This suggests that anthropogenic emissions of organic compounds from the city of Athens will have a negligible effect on the regional ozone budget.