It is well known that short-term variability in ozone column at a given location is almost solely caused by dynamical changes connected to tropospheric pressure systems. Long-term trends and interannual variability of ozone are also influenced by these dynamical changes. We address two questions, which are still under discussion: What is the impact of these dynamical changes on the observed long-term trend of ozone, and what is the quantitative contribution of the physical processes standing behind the dynamical variability to the trends and short-term variability? These processes are identified as horizontal isentropic transport and the vertical displacement of isentropes. We use a multiple regression model to analyze the variability of the total ozone column. The model includes a newly introduced explanatory variable based on the equivalent latitude profile at a given location. Ozone column data are taken from 8 high quality stations of the European Dobson spectrometer network. Results show that vertical displacements are the main contributor to short-term variability, and that 30%--50% of the long-term trend can be explained by long-term pressure changes.