A climatological study of rural surface ozone in central Greece

[摘要] Recent studies show that surface ozone levels at rural sites in Greece aregenerally high when compared with rural ozone measurements at northernEuropean sites. The area of SE Europe, including Greece, is not very wellmonitored regarding rural ozone in comparison to central and northernEurope. In order to have the best possible picture of the rural surfaceozone climatology in the area, based on the available data-sets of long-termcontinuous monitoring stations, the 10-year measurement records (1987-1996)of the Athens peripheral station of Liossia, (12 km N of the city center)and the urban background station of Geoponiki (3 km W) as well as the 4-yearrecord (1996-1999) of the rural station of Aliartos (100 km NW of Athens),are analyzed in this paper. The data for Liossia and Geoponiki stations arescreened for cases of strong airflow from rural areas (N-NE winds strongerthan 5 m/s). The variation characteristics of the average rural ozoneafternoon levels (12:00-18:00), with the best vertical atmosphericmixing, are mainly examined since these measurements are expected to berepresentative of the broader area. In all three stations there is acharacteristic seasonal variation of rural ozone concentrations with lowestwinter afternoon values at about 50 μg/m³ in December-January andaverage summer afternoon values at about 120 μg/m³ in July-August,indicating that high summer values are observed all over the area. The ruralsummer afternoon ozone values are very well correlated between the threestations, implying spatial homogeneity all over the area but also temporalhomogeneity, since during the 13-year period 1987-1999 the rural afternoonozone levels remained almost constant around the value of 120 μg/m³.

[学科分类] 大气科学