Trace constituents in the Austral stratosphere

Measurements of NO, NO2, HNO3, O3, N2O, CCl3F, H2O, CH4 and aerosol were made during balloon flights in the stratosphere over Australia at 23°S and 34°S from March to October 1979. These data and ground-based column density measurements of O3 and NO2 are presented and compared with previous measurements of the same species in the southern hemisphere stratosphere. Diurnal variations of NO and NO2 are presented. These measurements show that there is a temporary reservoir which, during the daytime, releases perhaps one third of the total NOx present at sunset. Vertical and latitudinal variations of NOy (NO + NO2 + HNO3) and the partitioning between the three species are presented. There is a substantial increase in NOy towards high latitudes. HNO3 is a larger fraction of NOy in the mid-latitude westerlies compared with the subtropical easterlies as observed in a mixing event involving air from higher latitudes. Unusual profiles of aerosol, CCl3F and NO were observed that can be explained by an intrusion of air from lower altitude into the 27 to 32 km height range in the equatorial and temperate latitudes of the southern hemisphere during March to May 1979.