Results and Discussion. According to the analysis of
the climatological data, the coldest temperatures over
Antarctica typically occur in August–September (depletion
of the ozone layer), while temperatures usually begin to
warm by early October (the ozone layer starts to recover).
However, the corresponding data analysis shows that in
late September 2002 (especially during 21–26/09/2002)
some unusual synoptic features have occurred regarding
the stratospheric weather patterns over Antarctica. In
particular, an inspection of the polar stereographic charts
(10 hPa geopotential height) shows that the basic polar
vortex in the stratosphere of the southern hemisphere
was step-by-step elongated up to the occurrence of a
dramatic change the polar vortex split into two centres. To
be more concrete, on September 21 the basic polar
vortex elongated (as shown by the roughly elliptical height
contours) and centered just off the pole. On September
22, this structure rotated eastward and elongated further
with a weakening of the polar vortex (accompanied by a
quasi-stationary anticyclone which appeared much earlier
than normal) at the middle. On September 23 and 24 this
rotation and elongation continued, and the weakening
became gradually stronger. On September 25, an
opposite to the first, secondary anticyclone started to
develop, and