Measurements of N2O and O3 during the Airborne Arctic Stratospheric Expedition have been composited using the potential vorticity and potential temperature of each measurement as coordinates. For ozone, data sources included the ER-2 and balloon ozonesonde in situ measurements, DC-8 DIAL lidar, and SAGE satellite profiles. For N2O, only ER-2 data were used. These chemical composites have been reconstructed onto average meteorological fields for the mission in a latitude-altitude cross-section yielding a picture of the chemical composition of the polar vortex during this period. Tracers inside the vortex show an apparent descent of about 2 km relative to those outside, resulting in an apparent chemical edge on isentropic and isobaric surfaces. ¿ American Geophysical Union 1990