Data from 5 years of continuous surface ozone measurements made at 16 European and African stations, located on a meridional chain between 69.5¿ N and 34¿ S, are presented. The analysis of monthly averages exhibits an annual sinusoidal variation with mean, amplitude, and phase characteristic for each latitude. Thirty-four meridional cross-sections of ozone in the high troposphere were measured aboard commerical jetliners. Both ground-based and aircraft measurements indicate enhanced stratospheric-tropospheric ozone injection at about 30¿, 45¿, and 65¿ N. The average ozone injection fluxes vary between 3¿1010 mol/cm2 s at the equator and 10¿1010 mol/cm2 s at the main injection latitude.