• Antarctica;
  • ozone;
  • aerosols;
  • chemistry


[1] Trace gases, submicron particle size distributions, and bulk filterable halogen content were measured on Ross Island, Antarctica, in austral spring 2007. During several surface level, partial ozone depletion events, enhanced submicron particle concentrations, and changes in filterable halogens were observed. These events were characterized by ozone depletions of 5–15 ppbv for durations between 6 and 48 h and associated with threefold-to-fourfold increases in submicron particle mass (PM1.0) over backgrounds of approximately 100 ng m−3. Peak particle number densities were centered on a mode at 500–600 nm in diameter, which is consistent with wintertime sea-salt aerosol size distributions. Filterable chloride also increased during these events, consistent with aerosol being of oceanic origin. Ozone depletion and particle enhancement events were accompanied by increasing temperatures and winds, suggesting that halogen-containing aerosol is generated from windblown snow and brine from the snow pack or sea ice near the ice edge.