Interannual changes of total ozone and Northern hemisphere circulation patterns

Abstract

Linear regression accounting for the quasibiennial oscillation, the 11-year solar cycle, stratospheric volcanic aerosol loading, and a long-term trend, accounts for 53% of the interannual ozone variance observed in February at Hohenpeissenberg (48°N, 11°E). When tropospheric circulation patterns are added to the regression, a substantially larger fraction (81%) of the observed total ozone variance can be described. The Polar Eurasia circulation pattern, negative anomalies of tropospheric geopotential height over Greenland and Arctic Canada coupled to opposite anomalies over Central Europe and North-Eastern China, is essential in accounting for interannual variations of February total ozone at Hohenpeissenberg. A large part (≈ 25%) of the February long-term ozone decline at Hohenpeissenberg appears to be related to a more frequent positive phase of this pattern. Circulation could influence ozone directly through transport, or indirectly enhance Arctic chemical ozone depletion through cold temperatures. Since climate change in the northern hemisphere winter manifests itself in a pattern very similar to the Polar Eurasia pattern, this study gives a strong indication that climate change might affect the stratospheric ozone layer.