AN ANALYSIS OF THE DISTRIBUTION OF NITROGEN-DIOXIDE IN THE SOUTH-EASTERN MEDITERRANEAN FOR THE PERIOD 1985-1989

The abundance of ozone in the stratosphere depends upon a photochemica l cycle in which nitrogen dioxide (NO2) plays a predominant role. Alth ough the zonal mean cross-sections for NO2 averaged for 34 months have been calculated-on the basis of LIMS data-lack of detailed informatio n at local or regional scale could result in difficulties in terms of modelling the distribution of ozone in the stratosphere. In this paper we use SAGE II measurements to calculate the altitude profiles of NO2 mixing ratios for the geographical region 15 to 30 degrees E and 32.5 to 42.5 degrees N for the period 1985 to 1989. Analysis of the findin gs shows that NO2 experiences higher values in summer months, that the NO2 maximum mixing ratios decrease from 1985 to 1989, that maximum mi xing ratios are found at an altitude of approximately 33 km, with vari ations depending on season and year and that NO2 mixing ratios for the period 1985-1989 are higher compared to the relevant mixing ratios fo r 1979-1981.