Assessing the impact of the New Athens airport to urban air quality with contemporary air pollution models

The new airport of Athens will be constructed in the Spata area to the east of the Athens basin. In an attempt to study how the airport operation influences air quality in Athens, the wind flow and pollutant transport in the Athens basin and the Spata area are studied by applying a set of contemporary models, all constituents of the EUMAC Zooming Model (EZM): (1) the nonhydrostatic prognostic mesoscale model MEMO for simulating air flow and the dispersion of inert pollutants, and (2) two photochemical dispersion models, the three-dimensional model MARS and the three-layer model MUSE for describing the dispersion of reactive pollutants. Simulations were performed for meteorological conditions favouring the occurrence of air pollution episodes. Emphasis is put on the influence of the airport emissions on air quality assuming that the airport is operating either at its old location (Hellenikon) or at Spata. Comparison of simulation results for one selected scenario achieved with all three models reveals similar diurnal variations of nitrogen oxides in the Athens basin and the Spata area. The model results show that under conditions favoring air mass penetration from Athens to the Spata area the resulting pollutant transport causes an increase in air pollution levels without, however, leading to the exceedance of air quality standards. In the opposite case, the pollutant transport cannot have a noticeable adverse influence on the Athens air quality because of both the relatively high urban air pollution levels and the fact that the penetration depth is small.