Influence of the Antarctic Ozone Hole over the South of Brazil in 2008 and 2009

Abstract

The Antarctic Ozone Hole is a cyclical phenomenon which occurs over the Antarctic region from August to November each year. The polar vortex turns it into a restricted characteristic dynamics for this region. However, when the polar vortex begins to weaken in October, air masses with low ozone concentration could escape and reach regions of lower latitudes. This study presents the influence of the Antarctic Ozone Hole over the South of Brazil in the years 2008 and 2009. To verify the events of influence, data of ozone total column from Brewer Spectrophotometer installed at the Southern Space Observatory (29.42° S, 53.87° W), in Sao Martinho da Serra, South of Brazil was used, and OMI Spectrometer overpass data for the same location. In addition to Brewer and OMI data, potential vorticity maps using GrADS (Grid Analysis and Display System) generated with the NCEP data reprocessed, and backward trajectories of air masses, using the HYSPLIT model of NOAA, were analysed. Ozone total column for the days with lower ozone were compared with the climatological average of twenty years for September and October. For statistical reasons, only the days with ozone total column lower than climatological monthly average minus 1.5 times the standard deviation, were analysed. Considering only the days with less ozone, increased absolute potential vorticity and backward trajectories indicating the origin of polar air masses, 3 events in 2008 and 2 events in 2009, with an average decreased about 9.7 ± 3.3% when compared with climatological means, were observed.