A CLIMATOLOGICAL ANALYSIS OF 4-DAY BACK TRAJECTORIES FROM ALIARTOS, GREECE

This study presents a flow climatology for Greece based on a survey of climate and synoptic weather types, and a five-year trajectory climat ology. Isobaric back trajectories at the 850 and 700 hPa levels were c alculated daily at 0 and 12Z for the years 1983-1987 for the Aliartos, Greece EMEP station, using the Air Resources Laboratory (ARL) traject ory model. Trajectories were classified by direction and speed to exam ine monthly, seasonal and annual variability in flow characteristics. The main features of the flow are similar from year to year. Dominant transport sectors are NW and W, followed by N, SW and NE. Four-day bac k trajectories from NW and W usually originate from beyond 2,400 km, w hile those from other directions tend to originate closer to Greece. C ases of most rapid transport occur in January and December. Potential pollutant source regions are identified corresponding to preferred tra jectory directions and distance ranges.