Atmospheric conditions associated with high and low ozone concentrations in the lower troposphere over the Aegean sea

In this study the vertical ozone profiles during summertime (June to August) of the MOZAIC (Measurement of Ozone and Water Vapor by Airbus in Service Aircraft) Project over the eastern Mediterranean airports of Heraklion and Rhodes in the Aegean Sea, have been analyzed in order to identify the major factors determining the ozone variability in the lower troposphere over this area. In total 42 ozone profiles have been examined, which have been collected during a 10-year period (1996-2006). In addition, the corresponding vertical profiles of temperature, relative humidity, carbon monoxide and wind speed have been also examined in parallel. The vertical summer ozone profiles have been classified into groups of highest and lowest ozone levels in the free troposphere (at the 3000-5000m and 1500-3000m layers) and the corresponding composite weather maps of geopotential heights have been plotted and their examination was focused on the Aegean Sea area.
From the data analysis it comes out that for the examined area, in the lower troposphere but also within the boundary layer the role of the synoptic weather conditions and the associated large-scale transport of air masses, especially anticyclonic subsidence, seem to be more important in understanding the ozone variability than the local or regional short-term ozone photochemical production.