[en] The main object of this paper is to present in one place a series of meteorological analyses to aid the interpretation of the in situ Airborne Antarctic Ozone Experiment (AAOE) observations. Maps and sections of meteorological variables derived from the United Kingdom Meteorological Office global model are presented for ER-2 and DC-8 flight days. Analyzed temperatures and winds are generally in good agreement with AAOE observations at all levels. Minor discrepancies in winds and temperatures are evident, particularly at DC-8 altitudes, and are discussed in the paper. Model analyses show temperatures at 60 degree W cold enough to saturate water at 1 part per million by volume as late as September 14 and that following that date a sudden increase in the temperature at all levels within the vortex precludes further saturation at low water vapor mixing ratios. Maps of potential vorticity are presented on the 428-K potential temperature surface for the AAOE flight days. These show that the vortex is essentially circumpolar although there are periods when major distortions are apparent. At the 428-K potential temperature level, the area of the vortex, as defined by the areas enclosed by selected potential vorticity contours, remains approximately constant throughout the AAOE

[en] A photochemical model consisting of 40 species and 107 reactions is integrated along 80 day air parcel trajectories calculated in the lower stratosphere for the springtime Antarctic. For the trajectory starting at 58 degree S, which may be regarded as outside the circumpolar vortex, only a small change in O₃ occurs in the model. In contrast, for the air parcel starting in the vortex at 74 degree S, the O₃ concentration is reduced by 93% during the 80 days from the beginning of August to late October. The model results for several species are compared with measurements from the Airborne Antarctic Ozone Experiment and, in general, good agreement is obtained. In the model, the denitrification of the air parcels in polar stratospheric clouds increases the amount of chlorine present in active form. Heterogeneous reactions maintain high active chlorine which destroys O₃ via the formation of the ClO dimer. Results of calculations with reduced concentrations of inorganic chlorine show considerably reduced O₃ destruction rates and compare favorably with the behavior of total O₃. The remaining major uncertainties in the photochemical aspects of the Antarctic ozone hole are highlighted