Numerical simulations of the meteorological and dispersion conditions during an air pollution episode over Athens, Greece

In this study a summer air pollution episode from 6 to 8 August 1994 over A thens, Greece, is investigated through advanced atmospheric modeling. This episode was reported from the air quality monitoring network, as well as fr om research aircraft measurements performed during this period for the Tran sport and Transformation of Air Pollutants from Europe to the East Mediterr anean region project. The meteorological conditions prevailing during the p eriod 6-8 July 1994 are analyzed based on simulations performed with the Co lorado State University-Regional Atmospheric Modeling System and on the ava ilable surface and upper-air observations. Indeed, the synoptic settings in duced favorable conditions for the development of local-scale circulations, which defined the poor dispersion conditions over the area. The dispersion of the urban plume of Athens is studied with the use of the Hybrid Particl e and Concentration Transport package model. The urban plume of Athens is t racked down the Saronic Gulf and the eastern coast of Peloponnisos, more th an 200 km southward from the Athens Basin in good agreement with the resear ch aircraft observations.