Statistical Evaluation of the Weekend Ozone Effect (WOE) in Istanbul

In this study, a two-step statistical approach was used to quantify the phenomenon known as the ” WeekendOzone Effect” (WOE) in which higher ozone concentrations in urban areas are evident on weekends thanon weekdays. In the first step, Fisher’s Least Significant Difference (LSD) procedure was used todiscriminate among the means of the calculated ratios. In the second step, weekly cycles were detectedusing spectral estimation by the Burg method, a powerful non-parametric method for spectral estimation.The method was used to evaluate the data for two stations in Istanbul, Kadikoy and Sarachane, for theperiod 2000 and 2005. Significant differences were observed between the stations. While the Kadikoy datashowed a typical and very clear WOE, the same phenomena was not clearly evident in the Sarachane data.The most probable reasons for this difference is discussed and the main attribute of the differentcharacteristics of the daily traffic activities within the regions.