Air Quality Analysis And Modeling In Urban Region Of Patras, Greece

摘要

A systematic analysis of atmospheric concentrations of primary pollutants, in urban Patras, during a 3-year period (2001-2003) is presented. For all primary pollutants, a seasonal variation with minimum in summer and maximum in winter was observed, except for O_3 where the exact opposite occurred. The PM_(10) shows the less marked seasonal cycle. Downward trends of SO_2, CO, O_3, PM_(10) (Station "B") and of CO, NO_x (Station "A"), as well as upwards of NO_x (Station "B") and of SO_2. PM_(10) (Station "A") were identified. Concerning the PM_(10), strong excess of the limits during the period 2001-2003 was observed. According to the limit of 2005, the concentration values in stations "A" and "B", were up to 29.7% and 12.1% of the limits, respectively. A strong (CO, NO_x, PM_(10)), moderate (NO_2), and indifferent (SO_2) positive correlation were estimated. A multiple regression model for the prediction of the 2nd eight-hour ozone concentrations in relevance to 1st eight-hour ones, and the weather features (cloud, precipitation and temperature), is developed. Validation statistics were used to assess the relative accuracy of the model. Analysis, concerning the models' ability to forecast real ozone episodes, was also carried out. The forecast skill of regression model for ozone episode days was found to be quite satisfactory, with a detection rate of 63.83 % and 73.85 % for O_3 >180μg m~3 and O_3 >200 μg m~3, respectively.