The effective meridional turbulent diffusivity DT(Kyy) of ozone at the 520 K isentropic surface level has been computed from the satellite maps of total ozone concentration (Total Ozone Mapping Spectrometer (TOMS)) and the available winds (United Kingdom Meteorological Office (UKMO)) in the Antarctic stratosphere for the springs of 1992 and 1994. We found that for a fixed rms north-south velocity, the turbulent diffusivity of ozone decreases when the anisotropy (A≡east-west over north-south winds) increases. This result stands for anisotropies ranging from A>1 up to A=25, and a sill exists at A≈10. The effect is particularly pronounced at the edge of the vortex where the corresponding meridional turbulent ozone flux also decreases with A. We show that the break of meridional mean transport is due to a homogenization process in the transverse (east-west) direction, at the edge of the vortex (60¿). This study gives a new physical insight in favor of the impermeability of the vortex. ¿ 1999 American Geophysical Union