Inter-annual variability of high-latitude stratospheric ozone from satellite observations and model calculations

It has been shown that the inter-annual variability of total ozone in the polar regions of both hemispheres is highly correlated with the flux of planetary waves into the stratosphere. In order to estimate the relative importance of transport and chemistry on the inter-annual variability of high latitude ozone, we use a chemical transport model (CTM) together with observations from the Global Ozone Monitoring Experiment (GOME) and the Total Ozone Mapping Spectrometer (TOMS). We find that the expected inter-annual variability of total ozone in the northern hemisphere in the absence of polar ozone depletion is not significantly different from the observed variability, in contrast to the southern hemisphere, where chemical ozone depletion is the dominant effect. However, the large uncertainty of the planetary wave flux in current meteorological analyses is a limiting factor for modeling the inter-annual variability of total ozone.