An unusual stratospheric ozone decrease in the Southern Hemisphere subtropics linked to isentropic air-mass transport as observed over Irene (25.5° S, 28.1° E) in mid-May 2002

Abstract

An unusual stratospheric ozone decrease in the Southern

Influence of the Antarctic Ozone Hole over South of Brazil in 2010 and 2011

“…Similar events of low ozone air masses intrusions from Antarctic ozone hole toward mid latitude like those analyzed here were also observed over South America (Kirchho et al, 1996;Perez et al, 2000), Southern Africa (Semane et al, 2006) and New Zealand (Brinksma et al, 1998). …”

“…e PV variation over isentropic surfaces can be used to transport ozone in stratosphere (Jing et al, 2005). An increase at the APV indicated a polar origin of the poor ozone air mass (Narayana Rao et al, 2003;Semane et al, 2006). e polar origin of an air mass can be show also with backward trajectories (Gupta et al, 2007).…”

A major event of Antarctic ozone hole influence in southern Brazil in October 2016: an analysis of tropospheric and stratospheric dynamics

“…Thus, PV is used in studies that correlate potential vorticity with chemical constituents such as ozone, water vapor, and nitrous oxide on isentropic surfaces (adiabatic surfaces where the potential temperature remains constant as temperatures and pressure vary) in the lower troposphere (Schoeberl et al, 1989). This type of analysis aims to verify whether the air masses are originated in the Antarctica region, showing an increase in APV considering the previous days of the event, or in the equatorial region in the case of an APV decrease (Semane et al, 2006). Images from the OMI satellite (OMI-ERS2/NASA, 2017) were also used.…”

“…In the lower stratosphere, EPV is assumed to be conservative on isentropic surfaces for periods of about one week (Orsolini, 1995). For longer periods, diabatic transport across isentropic surfaces occurs due to radiative cooling and warming of air masses; thus, the diabatic advection term should be taken into account in the EPV equation (Bencherif et al, 2003;Semane et al, 2006). The MIMOSA model produces advected APV files at different isentropic surfaces and for global spatial coverage.…”

Weather Condition Associated With Influence of the Antarctic Ozone Hole Over South of Brazil on October 21th, 2011

“…In these days, the stratospheric origin of ozone-poor air masses is verified through the analysis of Potential Vorticity (Semane et al, 2006) over isentropic surface of 620 K potential temperature, using daily parameters provided by NCEP/NCAR reanalysis, for the purpose of checking the dynamic pattern of the stratosphere. Retroactive trajectories of air masses were made by HYSPLIT model of the NOAA confirms the polar source of ozone-poor air mass and your passing by the polar region.…”