Ozone measurements at British Antarctic Survey stations

Ozone measurements have been made regularly at Argentine Islands and Halley Bay since 1957. A recent critical review of the data revealed inconsistencies in the extraterrestrial constants adopted for the various spectrophotometers used. These have been resolved and the data recalculated to give consistent series. The variations in total ozone on differing time-scales, and their relation to variations in the temperature of the lower stratosphere, are discussed. A major increase in total ozone occurs in the course of the breakdown of the winter polar stratospheric vortex. It is often preceded by large quasi-periodic fluctuations associated with baroclinic waves in the vortex. The response of the vortex to these waves is discussed and comparisons made with conventional data from lower latitude stations and with satellite data on Southern Hemisphere sudden warmings. Long-term trends in total ozone are shown to be small at both stations. A recent global analysis of ozone trends is noted