Satellite measurements over the Arctic region (63¿--90¿ N) have shown that the amount of ozone in the atmospheric column decreased and exhibited increased variability during the last decade. We here show that for the period 1992--2000 the major part (75%) of the observed ozone decrease in March in the Arctic and most of the variability may be explained by winter/spring ozone depletion in the polar vortex. A good correlation (0.96) between the Arctic ozone decreases and the polar vortex winter/spring ozone depletion is found, which is partly a result of coupling between dynamical and chemical effects.