Numerical Study of Regional Air Pollution Transport and Photochemistry in Greece

Abstract

The aim of the present project is to study the transport and photochemistry of regional air pollution in Greece using numerical models, a higher-order turbulence closure dynamic model coupled with an Eulerian photochemical dispersion model. The model used for the simulation of the three-dimensional wind field and the boundary layer structure is developed at the Department of Meteorology, Uppsala University (MIUU) while the calculations of pollutant concentrations were performed using the Urban Airshed Model (UAM).

For the purposes of the present study, a new inventory for the biogenic emissions is prepared comprising hourly emissions from forest canopies and other vegetation as a function of temperature, sunlight (cloud cover), and the coverage of each vegetation category. The VOC speciation of the inventory is suitable as input to the UAM model. In addition, the industrial and traffic emissions were estimated for the whole region with a resolution of 10 × 10 km and used as input for the UAM.

One summer day was selected for simulation during the period of the PAUR project, when the conditions were characterized by a moderate-to-strong synoptic forcing. The resulting meteorological conditions reveal a northerly flow prevailing over the Aegean sea which is known as Etesians. In the areas that are influenced by the Etesians, the development of local circulations is not favored and the flow field is rather homogeneous. The predicted concentrations of air pollutants are in good agreement with observations at rural sites.