Moderating the influence of meteorological conditions on ambient ozone concentrations

Because ambient ozone concentrations are so strongly influenced by stochastic and seasonal variations, it is difficult to assess the effectiveness of regulatory controls in improving ambient ozone air quality. The purpose of this paper is to present a method for moderating the influence of meteorological fluctuations on ambient ozone levels. Techniques presented here account for temperature and other meteorological variables that affect ambient ozone concentrations. To this end, we have examined the correlation between several meteorological variables and ozone concentrations. In addition, we have evaluated trends in ozone time series after removing the effects of these variables on ozone concentrations. The results indicate that inclusion of two meteorological variables strengthens the relationship between ozone and meteorological effects. Moreover, the meteorologically-independent ozone time series at one of the locations studied had a significant trend that was not detected in temperature-independent ozone concentrations.