Intra-annual relationships between polar ozone and the SAM

[1] Observed co-variations between polar total column ozone and the Southern Hemisphere Annular Mode (SAM) during 1962–2004 are presented and evaluated in a chemistry-climate model (CCM). Results show that austral spring total column ozone variability at South Pole is significantly related to the SAM, perhaps up to four months later; this relationship is only seen in simulations that include ozone depletion. The austral spring SAM also is linked to following late spring – early summer total column ozone over the polar cap, since both respond to the wave-driving of the stratosphere. Overall, the CCM captures many of the observed ozone-SAM links, but over-predicts the relationship between spring ozone and austral summer SAM, as a consequence of the delayed breakdown of the polar vortex in the CCM.