Data Analysis and Model Comparison of Ozone Above Lake Michigan

Abstract

Routine measurements of ambient ozone in the air mass over Lake Michigan were conducted from 2008-2010 using ferry routes from Milwaukee, WI to Muskegon, MI. This created an exhaustive data set of off-shore observations at lake level. Combined with temperature data, the observational data from these transects were evaluated for spatial and temporal trends and compared to the National Ozone Air Quality Forecast Model to test the ability of the model to predict ground level ozone in the region. The model bias was found to be consistently high, and complex trends emerged from the observational data with respect to ferry location and time of day. The extent that these trends can be used to pinpoint difficulties in determining the parameters of the photochemical and meteorological conditions over Lake Michigan in the model will continue to be investigated.