Regional Modeling of Weekday/Weekend Ozone Changes in the Midwestern U.S

摘要

The weekend ozone effect refers to changes in ground-level ozone concentrations on weekends resulting from anthropogenic emission changes from weekdays and weekends. This study applied a three-dimensional photochemical grid model for a three-month summer period to examine the weekend ozone effect in the Midwestern U.S. at both urban and regional scales. The model generally reproduced the observed daily maximum 1-hour and 8-hour ozone and also correctly predicted weekend changes in the VOC-to-NOx ratio. So-called dynamic evaluation of the modeled weekend ozone changes throughout the summer revealed that meteorology had a bigger impact on the summer 2005 weekend ozone effect than anthropogenic emission changes partly because meteorology strongly influences biogenic emissions.