Investigação da dinâmica do ozônio estratosférico sobre a América do Sul: casos de eventos de vírgula

Abstract

Given the importance of the ozone layer to life on the surface, an investigation on the dynamics of stratospheric ozone and its interaction with troposphere systems are conducted in this study. Being the focus of work the events of "ozone hole" extension over South America, here titled as comma events. The work was conducted out for the period from 1979 to 2016 only for the months of August, September, October and November, those are the months in which the ozone hole is unstable. The data used were daily average ERA - INTERIM (European Center for Medium - Range Weather Forecasts) with spatial resolution 1x1º for whole Southern Hemisphere. An analysis of the total ozone column, temperature in 100 hPa, zonal wind in 100 hPa and 200 hPa and potential vorticity (PV) in 600 K fields are performed through the mean of the period and the mean for days with a comma event, in addition to the difference between these two means and the analise for some events. In these analyzes it was found that during the comma events a dipole in PV field and zonal wind in 200 hPa were associated with Rossby wave breaking and the intrusion events. In addition to the mass mixture that occurred between the "arm" of comma and the belt of high ozone concentrations. In a second part, surface analyzes were performed in the mean sea level pressure and geopotential (500 hPa) fields, zonal wind (200 hPa) and temperature (850 hPa), as well as the vertical cut in the latitude of 50ºS for the zonal wind and temperature. The influence of the vortex was verified on smaller latitudes and altitudes, showing the connection between troposphere and stratosphere. During the coma events on South America there were anticyclones, associated to large amplitude between the crest and trough.