An overview of the Gulf Coast Ozone Study

With the promulgation of the new longer-term (8-hour average) standard for ozone, the coastal areas of Florida, Alabama, Mississippi, and Louisiana may be designated nonattainment due to the unique meteorological characteristics of the coastal area, which includes potential recirculation of pollutants due to the gulf breeze, and the recent increase in population in these areas. The Gulf Coast Ozone Study (GCOS), sponsored by the four states and Southern Company, is designed to provide technical information related to 8-hour ozone issues in the area, and to provide a basis for meeting regulatory modeling requirements and for longer-term decision making. The study consists of episode selection, data analysis, meteorological modeling using MM5, and air quality modeling using the UAM-V modeling system. The study focuses on the coastal communities of Pensacola, Mobile, Pascagoula, Port Bienville, New Orleans, and Baton Rouge, but includes a modeling domain encompassing the entire Southeast U.S. This paper will present an overview of the study, including meteorological and photochemical modeling results for three multi-day episodes. The modeling effort will provide the basis for the assessment of future-year control strategies for the area for the year 2005.