FKL is the atmospheric research station of the Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete. The station is situated at Finokalia (35°20'N, 25°40'E ) on the north coast of Crete. The nearest large urban centre is Heraklion with 150000 inhabitants located 70 km west of Finokalia. The station is located at the top of a hilly elevation (250 m asl) facing the sea within a sector 270° to 90°. No significant human activities occur at a distance shorter than 15 km within the above mentioned sector. The area is characterized by the existence of two well-distinguished seasons: the dry season (from April to September) mainly characterised by increased levels of pollution and biomass burning events and the wet season (from October to April). Important transport from Sahara (S/SW winds; occurrence up to 20%) takes place during the intermediate season (spring and autumn).