In this study, we report on the results from a comprehensive model simulation of regional ozone (O3) throughout a season in the eastern United States. The model is shown to perform better in terms of simulating seasonal, rather than episodic, characteristics of the regional surface O3 distribution. This finding suggests that it may be more appropriate to use models of this type to assess seasonal O3 patterns rather than following the current paradigm of developing regional control strategies based on event-specific simulations. ¿ 2000 American Geophysical Union