The spatial variability of total ozone at high latitudes in winter is explained by the vertical structure of planetary-scale waves. The location of the maximum in total ozone is governed by the phase shift with height of the waves, while the amplitude of the maximum depends on the phase and also on the vertical and horizontal mean-zonal ozone gradients. Abstract The spatial variability of total ozone at high latitudes in winter is explained by the vertical structure of planetary-scale waves. The location of the maximum in total ozone is governed by the phase shift with height of the waves, while the amplitude of the maximum depends on the phase and also on the vertical and horizontal mean-zonal ozone gradients.