A technique for forecasting enhanced ozone days in a complex sub-tropical coastal urban environment

Air mass based objective synoptic climatological techniques are becoming more frequent in air pollution climatology studies, particularly in the study of ozone. This paper assesses a statistical synoptic climatology of ozone episodes in Sydney, particularly its ability to isolate and predict enhanced ozone days. The climatology found that over 90% of ozone events that exceed current air quality goals in Sydney are associated with one synoptic category. However, almost half of the days falling within this category experienced ozone concentrations lower than air quality goals. These days have similar synoptic conditions, yet quite different ozone concentrations. The differences between days in this category that experience high ozone concentrations, and days predicted to have high ozone and yet receive only low pollution is examined.

A two-stage forecasting technique is presented for use in predicting ozone episodes in a sub-tropical coastal urban environment. Firstly, an air mass based synoptic climatological technique is suggested to isolate synoptic conditions associated with enhanced concentrations of ozone. Secondly, a multiple regression model differentiates enhanced and low ozone days within this synoptic situation.