Long-term variation of total ozone

The long-term variation of total ozone is studied for 1957 up to date for different latitude zones. The 3-year running averages show that, apart from a small portion showing parallelism with sunspot cycles, the trends in different latitude zones are dissimilar. In particular, where northern latitudes show a rising trend, the southern latitudes show an opposite (decreasing) trend. In the north-temperate group, Europe, North America and Asia show dissimilar trends. The longer data series (1932 ownards) for Arosa shows, besides a solar-cycle-dependent component, a steady level during 1932–1953 and a down-trend thereafter up to date. Very localised but long-lasting circulation patterns, different in different geographical regions, are indicated.