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Southern hemisphere winter ozone fluctuations
Author(s) -
Vigliarolo P. K.,
Vera C. S.,
Diaz S. B.
Publication year - 2001
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49712757216
Subject(s) - tropopause , climatology , atmospheric sciences , stratosphere , ozone , baroclinity , storm track , environmental science , southern hemisphere , northern hemisphere , middle latitudes , latitude , storm , zonal and meridional , jet stream , troposphere , geopotential height , extratropical cyclone , geology , meteorology , geography , physics , oceanography , jet (fluid) , precipitation , geodesy , thermodynamics
In this paper the relationship between ozone and atmospheric variability is explored over the southern hemisphere during the austral winter season, with special emphasis on synoptic transient fluctuations. The analysis of ozone tracks (or high‐frequency ozone variability) shows that they have a significant correspondence with storm tracks at middle and high latitudes. Moreover, ozone tracks maximize over the Indian Ocean slightly downstream of the storm‐track maximum, while over the Pacific region both ozone and storm tracks show decreased amplitudes. In particular, over southern South America (a region of climatological winter ozone minima and moderate to high ozone variability) the leading winter synoptic‐scale variability mode was identified through a rotated extended empirical orthogonal function analysis applied to the meridional‐wind perturbation at 300 hPa. The resulting mode is characterized by a baroclinic wave travelling eastward along subpolar latitudes, which maximizes near the tropopause level. Composite ozone fields based on this mode confirm, from a statistical point of view, the classical relationship between ridges (troughs) and minimum (maximum) ozone content. Furthermore, it is shown that dynamical processes in the upper troposphere and lower stratosphere associated with subpolar waves are responsible for the observed ozone distribution. This happens due to the barotropic equivalent vertical structure of the wave, together with the fact that ozone partial pressure maximizes near the level where the waves attain maximum amplitudes.