Total ozone characteristics associated with regional meteorology in West Antarctica

Abstract

We investigated the characteristics of the total ozone column (TOC) around West Antarctica (near the Weddell Sea) compared with ambient meteorological factors. For this analysis, we used ground-based and satellite TOC measurements as well as meteorology (air temperature, potential vorticity and wind field) from reanalysis data. Long-term patterns of TOC show the large year-to-year variation (e.g., maximumly ∼200 DU at King Sejong) but a steady recovering trend recently. Despite a generally consistent pattern, the TOC around West Antarctica did not correlate well between high- and low-latitude regions during austral spring; this result implies that the ozone hole area had a spatial variation over West Antarctica. The TOC pattern around West Antarctica correlated well with air temperature but showed a vertical difference; high positive correlations appeared in the lower stratosphere (maximumly R > 0.9 at ∼50–100 hPa height) showing enhanced ozone depletion in colder conditions, but negative correlations appeared in the upper stratosphere (minimum R < −0.8 at ∼5–10 hPa height) associated with the temperature dependence of ozone chemistry. The TOC also showed an interesting relationship to the potential vorticity: high positive correlation in the upper stratosphere (maximumly R > 0.9 at ∼500–600 K height) during the austral spring but a moderately negative correlation in the lower stratosphere (minimum R < −0.6 at ∼300–350 K height) during the austral summer. This peculiar pattern probably relates to the polar vortex intensification in the stratosphere and the stratosphere-troposphere airmass exchange near the tropopause. There were also some correlations with wind field (R = ∼0.4–0.6) showing air-mass mixing effects. These findings indicate a large meteorological influence on the spatiotemporal pattern of the TOC in West Antarctica.