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| Titel |
Structure and long-term change in the zonal asymmetry in Antarctic total ozone during spring |
| VerfasserIn |
A. V. Grytsai, O. M. Evtushevsky, O. V. Agapitov, A. R. Klekociuk, G. P. Milinevsky |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 25, no. 2 ; Nr. 25, no. 2 (2007-03-08), S.361-374 |
| Datensatznummer |
250015783
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| Publikation (Nr.) |
 copernicus.org/angeo-25-361-2007.pdf |
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| Zusammenfassung |
The quasi-stationary asymmetry of total ozone over Antarctica during spring
is studied by TOMS data during the period 1979–2005. Statistics on the
amplitude and longitudinal position of zonal anomalies are obtained from the
distribution of total ozone along seven individual latitudes at 5-degree
intervals between 50° S and 80° S. As shown by the September-November
means, the mid-latitude collar of ozone-rich stratospheric air has a
sub-Antarctic maximum with a mean location in the quadrant 90° E–180° E
and a total ozone level of about 380 DU between 50° S and 60° S.
The steady displacement and elongation of the ozone hole under the influence
of planetary waves causes a zonal anomaly of low ozone in the sector 0°–60° W
with total ozone levels of about 200 DU between 70° S and
80° S. Climatologically, the highest amplitude of the zonal anomaly is
57.2±13.5 DU (relative asymmetry of 32% between high and low ozone
levels) at 65° S latitude.
A significant eastward shift of approximately 45° in longitude is
observed in the total ozone minimum over the Weddell Sea – South Atlantic
sector during 1979–2005, whereas the zonal maximum is relatively stable in
location. Also apparent is a long-term shift in tropopause temperature
distribution in the region.
The geographical distribution of the zonal extremes in total ozone for the
seven latitudes shows that (i) the extremes exhibit sensitivity to the shape
of the Antarctic continent, (ii) the stationarity of the extremes increases
poleward above the edge of continent and (iii) the positions of the extremes
at the higher latitudes tend to follow the meridionally oriented elements of
orography. It is suggested that the radiative influence of Antarctica
contributes to the formation of this pattern. Anomalies in the horizontal
structure of the tropopause, which appear related to orography, support this
view.
Mechanisms involved in the formation and decadal change in the total ozone
asymmetry, as well as possible influences of the asymmetry on the
stratospheric thermal regimes and regional UV irradiance redistribution are
discussed. |
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