Ozone episodes in Athens, Greece. a modelling approach using data from the medcaphot-trace

Making use of the extended database of air pollution and meteorological measurements, which was created within the framework of the MEDCAPHOT-TRACE project, the performance of the Urban Airshed Model was evaluated for the Greater Athens Area (GAA). This model was also used to examine the effect on ozone of 36 scenarios of possible VOC and NOx reductions of entire area-wide emission. Although the GAA is characterised by complex topography and meteorological conditions as well as inhomogenious emission characteristics, the UAM predictions compare favourably with the existing observations. The EPA proposed statistical measures are met by the model, although there is a degree of uncertainty concerning the emission inventory (within a factor of 1.5–2). It is shown that ozone abatement strategy should focus mostly on VOC emissions controls rather than controlling NOx. The VOC reduction should be of the order of 30–40% in order to effectively reduce the ozone levels at the northern part of the GAA, down to the European Union’s limit of 90 ppb. This goal is not expected to be achieved before the year 2005.