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Summary

The annual cycle in total ozone and tropopause temperature are both tied to the intensity of the Brewer-Dobson circulation, modulated with a 30-50 day Madden-Julian oscillation. The maximum in total ozone does however also coincides with the Sun passing overhead in zenith during the dry season (6 September), which can be related to maximal photolysis of oxygen in the stratosphere. The MJO can be found in zonal wind at the tropopause, and also in the humidity levels of the lower troposphere. First studies, based on the equivalent potential temperature at the Earth surface, suggest an average upper limit of convection between 10-14 km. ECMWF calculations of potential vorticity over Paramaribo show negative values in the mid-troposphere, especially when the ITCZ lies to the south of Suriname. This indicates that the return flow of the upper Hadley branch does not come from the lower branch (north-east trade wind), but instead flows in from the Southern Hemisphere - suggesting a permeable ITCZ above about 7 km.