Convective transport of reactive constituents to the tropical and mid-latitude tropopause region: I. Observations

Measurements of ozone, reactive carbon and nitrogen, and other trace constituents from flights of the NASA WB-57F aircraft in the upper troposphere and lower stratosphere reveal that convection in the tropics can present a complex mix of surface-emitted constituents right up to the altitude of the lapse rate tropopause. At higher latitudes over the southern US, the strongest transport signal, in terms of constituent mixing ratios, occurred in the potential temperature range of 340–350 K or approximately over the altitude range of 9–11 km. Weaker convective signals were also seen up to near the tropopause. There was no evidence of convective transport directly into the lower stratosphere from these flights.