Within the European Arctic Stratospheric Ozone Experiment (EASOE) 1991/92, airborne UV-VIS spectral measurements of stratospheric OClO, NO2, and O3 were made by DOAS (Differential Optical Absorption Spectroscopy). The TRANSALL C160 was operated for the observation of the polar stratosphere from Kiruna (67¿N), Sweden, during four campaigns from December 1991 to March 1992. Inside the vortex, the highest vertical column densities of OClO, up to 12*1012 molec cm-2 at a solar zenith angle of 90¿, were observed during January and February 1992. The last OClO was detected on March 11 (4*1012 molec cm-2). Cross sections of the vortex showed the largest amounts of OClO within the core and lesser amounts in the vortex boundary. OClO was not detected outside the vortex within the detection limit which was 5*1012 molec cm-2 in December 1991 and about 2.5*1012 molec cm-2 in spring 1992. ¿ American Geophysical Union 1994