Global stratospheric distribution of halocarbons

A 16 yr database of stratospheric halocarbon profiles obtained by cryogenic whole air sampling and subsequent trace gas analyses is presented.Twenty-eight balloon ascents of cryogenic samplers were carried out at 44°N, supplemented by 2 balloon flights at 17.5°N and 3 flights at 69°N, between 1977 and 1993. The resultant vertical profiles of CCl4, CCl3F, CCl2F2, CClF3, CF4, CCl2FCClF2, CClF2.CClF2, CClF2CF3, CF3CF3, CH3Cl, CHClF2, CH3CCl3, CBrClF2 and CBrF3 were averaged using relative values with respect to tropospheric mixing ratios, yielding reference profiles for middle, low and high northern latitudes. In addition, latitude-altitude cross-sections of CCl3F, CCl2F2, and CH3CCl3 derived from the balloon data and additional aircraft data are shown for the northern hemisphere.