Fundamentally, the hypotheses that have been presented to explain the late winter loss of Antarctic ozone fall into two broad categories. One is that it is essentially chemical in origin, the other that it is caused by dynamically induced ingress of ozone-poor air from the troposphere. Whole-air samples collected aboard both the NASA ER-2 and DC-8 aircraft as part of the Airborne Antarctic Ozone Experiment (AAOE) were analyzed in a field laboratory set up at Punta Arenas, Chile. Mixing ratios obtained from gas chromatographic analyses of these samples are presented for CH4, CO, N2O, CFCl3, CF2Cl2, C2F3Cl3, CH3CCl3, and CCl4. Variations in the mixing ratios of these trace gases provide valuable information for both categories of postulation as indicators of the presence, motions, and history of air masses in the Antarctic atmosphere. Evidence of sustained subsidence is clearly indicated by comparison of CFCl3/N2O mixing ratios from the flights of September 16--29, 1987. ¿ American Geophysical Union 1989