Balloon-borne observations of the development and vertical structure of the Antarctic ozone hole in 1986

Abstract

A springtime deficit in Antarctic stratospheric ozone has been developing over recent years^1,2. Here we describe the vertical distribution of ozone which was measured at McMurdo Station, Antarctica (78 °S), using balloon borne sensors, on 33 occasions during the period 25 August–6 November 1986. These observations suggest a highly structured cavity confined to the 12–20 km altitude region. In the 17–19 km altitude range, the ozone volume mixing ratio declined from about 2 p.p.m. at the end of August to about 0.5 p.p.m. by mid-October. The average decay in this region can be described as exponential with a half life of about 25 days. While total ozone, as obtained from profile integration, declined only about 35%, the integrated ozone between 14 and 18 km declined more than 70%. Vertical ozone profiles in the vortex revealed unusual structure with major features from 1 to 5 km thick which had suffered ozone depletions as great as 90%.