AIRBORNE MEASUREMENTS DURING THE EUROPEAN ARCTIC STRATOSPHERIC OZONE EXPERIMENT - OBSERVATION OF OCLO

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 Spectroscop y). The TRANSALL C160 was operated for the observation of the polar st ratosphere from Kiruna (67-degrees-N), Sweden, during four campaigns f rom December 1991 to March 1992. Inside the vortex, the highest vertic al column densities of OClO, up to 12 10(12) molec cm-2 at a solar z enith angle of 90-degrees, were observed during January and February 1 992. The last OClO was detected on March 11 (4 10(12) molec cm-2). C ross sections of the vortex showed the largest amounts of OClO within the core and lesser amounts in the vortex boundary. OClO was not detec ted outside the vortex within the detection limit which was 5 10(12) molec cm-2 in December 1991 and about 2.5 10(12) molec cm-2 in spri ng 1992.