Prediction of the vertical profile of ozone based on ground-level ozone observations and cloud cover

A number of statistical techniques have been used to develop models to predict high-elevation ozone (O-3) concentrations for each discrete hour of day as a function of elevation based on ground-level O-3 observations. The analyses evaluated the effect of exclusion/inclusion of cloud cover as a variable. It was found that a simple model, using the current maximum ground-level O-3 concentration and no effect of cloud cover provided a reasonable prediction of the vertical profile of O-3 based on data analyzed from O-3 sites located in North Carolina and Tennessee. The simple model provided an approach that estimates the concentration of O-3 as a function of elevation (up to 1800 in) based on the statistical results with a +/- 13.5 ppb prediction error, an R-2 of 0.56, and an index of agreement, d(1), of 0.66. The inclusion of cloud cover resulted in a slight improvement in the model over the simple regression model. The developed models, which consist of two matrices of 24 equations (one for each hour of day for clear to partly cloudy conditions and one for cloudy conditions), can be used to estimate the vertical O-3 profile based on the inputs of the current day's 1-hr maximum ground-level O-3. concentration and the level of cloud cover.