MOZAIC climatology of O3
MOZAIC data collected at cruise altitude (between 8 and 12 km), north of 25°N have been referenced to the tropopause altitude (defined as a 30 hPa thick layer centered around the 2 pvu surface) to assess O3 and CO distributions in the UT (within 60 hPa below the tropopause) and in the LS (starting from 45 hPa above the tropopause) independently. Further details may be found in Thouret et al., 2006.
UT- These seasonal distributions clearly exhibit a summer maximum. We observe more ozone over the northeastern hemisphere compared to the northwestern one. Highest ozone concentrations are observed over the Mediterranean basin, while minima are sampled over south east Asia and Indonesia. High ozone over South America in SON probably reflect the influence of biomass burning occurring there at this time of year.
LS-These seasonal distributions clearly exhibit a spring maximum. Lowest ozone concentrations south of 40°N probably reflect the influence of tropical tropospheric air masses.