ESTIMATING THE SPATIAL-DISTRIBUTION OF OZONE CONCENTRATIONS IN COMPLEX TERRAIN

A method for estimating the spatial distribution of ozone concentrations has been developed, using ozone data from the Austrian ozone monitoring network. Starting from data of 9 days in summer 1991, when high ozone levers were observed, interpolation of the distribution of ozone concentration was performed. Ozone concentrations were assumed to be dependent on relative altitude (above valley ground) and on the time of day, and an empirical dependence function was created. This function was used all over Austria to create ''standard ozone concentrations'' for certain times of a day. The residuals to the actually measured ozone concentrations were determined at the monitoring sites and their spatial distribution interpolated using kriging techniques. Half-hourly maps were created as a combination of standard ozone concentration and residuals. Two of these maps of ozone concentrations over Austria are shown as examples, to demonstrate the diurnal behaviour. Calculation of uncertainty shows that the estimated ozone concentrations are usually within a range of 10 ppb of the measurements.