A recent ACP article by M.C. Parrondo and co-authors looked at 13 years of ozone soundings taken at the Antarctic Belgrano II station. These observations, taken inside the polar vortex when chemical ozone depletion occurs, are particularly valuable during the winter period, when satellite and ground-based observations based on solar radiation are lacking. The decrease of total ozone in spring was found to strongly depend on meteorological conditions, with greatest depletion occurring during coldest years (up to 59%) and considerably less occurring in warmer years (22%). In addition, they found that about 11% of total ozone loss in the layer where maximum depletion occurs takes place before the sun returns and occurs rather as a result of transport of low latitude air masses into the region, indicative of mixing inside the vortex. Comparison with observations from the South Pole station suggest that ozone loss rates at Belgrano are up to 25% lower than at the South Pole. The full abstract can be found here.