Ozone control strategy modeling and evaluation for Athens,Greece: ROG vs. NO x effectiveness and the impact of using different wind field preparation techniques

Summary The CIT photochemical model was used to investigate the effectiveness of ozone control strategies for Athens, Greece. A unique aspect of this study was the use of two different wind fields, one from a prognostic model, and the other derived with objective analysis procedures. This allows investigating to what degree the wind fields both derived using accepted methods, influence control strategy evaluation. Strategies investigated included reducing ROG and NO _x , and combinations of the two. For the period studied, the use of different meteorological field preparation techniques did not influence the direction of the ozone response to controls. In both cases (i.e. using prognostic or objective analysis wind fields), reducing NO _x led to predicted increases in ozone levels at the measurement stations, and ROG control lowered ozone. PAN concentrations respond similarly to ozone. However, use of the two different wind fields significantly impacted the degree and spatial locations of the responses. Use of the objective analysis fields showed greater response to emission controls because of the lower wind velocities generated. The influence of the biogenic emissions were found to be small. Also, a number of key data necessary for future studies of this kind were identified, as well as modeling domain questions.With 14 Figures