Variability of the Antarctic Ozone Hole during the Past Decade as Dictated by the Stratospheric and Tropospheric Meteorology

During the past ten years the Antarctic ozone hole has been quite variable in size and duration. For instance, the 2006 ozone hole was both large and long lived, while the 2002 and 2004 ozone holes were small and short lived. The reason for this can not be due to the available amount of ozone depleting substances as the amount of equivalent effective stratospheric chlorine (EESC) in the stratosphere has been close to or at its peak amount. This variability can only be attributed to the meteorology during the Southern Hemisphere (SH) winter and spring. It is well known that variability in the meridional flux of heat and momentum in the lower stratosphere from the mid-latitudes to the high latitude determines how cold and large the polar vortex becomes. The timing and number of instances of these flux episodes also determines how long into the spring the polar vortex exists. These flux episodes are fueled by upward propagating waves from the troposphere. There is evidence that the phase of the quasi biennial oscillation (QBO), the phase of El Nino Southern Oscillation (ENSO), and the southern annular mode (SAM) are the primary components of this source. Using the NCEP Reanalysis 2 data we will present how well the above three factors correlate with the size and duration of the ozone hole and the polar vortex. We will also address what the physical mechanisms are behind these correlations.