Driving Force of Total Ozone in the Northern Midlatitudes: An Analysis based on Data from Two Stations

In this paper, the slow feature analysis (SFA) method is employed to derive driving forces from the long-term monthly mean total ozone time series observed in two ground-based stations in the northern mid-latitudes. The wavelet transformation technique is then used to analyze the time scale structure of the derived driving forces. The slow feature analysis results show that the explosive volcanic eruptions have a significant influence on short-term ozone changes. The wavelet analysis results indicate that the driving forces of total ozone time series exhibit different time scale variations, which are mainly associated with solar activity cycles and quasi-biennial oscillation (QBO) cycles.