THE VARIATION OF AVAILABLE CHLORINE, CLY, IN THE ARCTIC POLAR VORTEX DURING EASOE

Whole air samplers were flown on large balloons that were launched from Kiruna (67.9-degrees-N, 21.1-degrees-E) in the period from 30 November 1991 until 20 March 1992 during EASOE. Thirteen vertical profiles of the CCl2F2 mixing ratio were obtained from the analyses of stratospheric air samples that were collected at altitudes between about 10 and 31 km. An empirical correlation function derived from simultaneous profile observations of CCl2F2 and the five other most abundant organic chlorine species was used to determine the vertical distribution of total organic chlorine (SIGMA Cl(org)) for each flight. These profiles allowed to estimate vertical profiles of the mixing ratio of total available chlorine, Cl(y), and the temporal variation of its column abundance.