PHOTOCHEMICAL OZONE PRODUCTION IN THE RURAL SOUTHEASTERN UNITED-STATES DURING THE 1990 RURAL OXIDANTS IN THE SOUTHERN ENVIRONMENT (ROSE) PROGRAM

Extensive measurements of ozone and its photochemical precursors and c oproducts were made in the 1990 Rural Oxidants in the Southern Environ ment (ROSE) program. Peroxy radical production, loss, and partitioning are described at a rural site in Alabama, showing the important role that biogenic organic compounds play in ozone production. Estimates of the peroxy radical concentration obtained by four methods along with the measured nitric oxide level are used to predict the instantaneous rate of photochemical ozone production at the site. The four methods a gree on the diurnal behavior of peroxy radicals and ozone production r ates, while consistent discrepancies between the methods generally are within their combined uncertainties. Selected aircraft measurements a re used to derive ozone production rates above the ground site, with t he highest rates occurring in the boundary layer and in industrial plu mes. The dependences of peroxy radical concentration and ozone product ion rate on the level of nitrogen oxides exhibit good agreement betwee n the various methods and are consistent throughout the lower troposph ere. Surface deposition and entrainment are shown to be as important a s photochemical production in determining the diurnal evolution of ozo ne at this site.