Combining in situ measurements of nitrous oxide, total water, and NOy with meteorological data, including potential vorticity, taken during the 1987 Airborne Antarctic Ozone Experiment, a consistent picture emerges of a gradual poleward movement of air extending from about 10¿ in latitude outside the boundary of the ozone hole to about 5¿ inside. The data analysis is concentrated in the potential temperature range of 425--450 K, corresponding to geometric altitudes of 17.5--19 km. Evidence of ongoing diabatic cooling throughout this region is presented, and cooling rates of about 1.75 K in potential temperature per day (approximately 0.8 K per day in temperature at constant pressure) are calculated from the data outside the boundary of the ozone hole. An interpretation of the data is presented that describes the movement of air that has come from lower latitudes into the ozone hole, as diabatically descending and spiraling poleward. The result of this spiraling motion is a dominantly advective flow of ozone rich air across the boundary and into the ozone hole. This simple picture precludes requiring extensive isentropic mixing with accompanying vertical descent to maintain the steep poleward isentropic gradients found in nitrous oxide. Data are presented to show that the necessary accompanying outflow of stratospheric air from within the ozone hole occurs at potential temperatures less than 425 K and that, during the mission, there was no significant transport of processed air across the boundary and out of the ozone hole from 425 to 450 K. Arguments involving conservation of angular momentum are also used to support this model. ¿ American Geophysical Union 1989