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| Titel |
The mean meridional circulation and midlatitude ozone buildup |
| VerfasserIn |
G. Nikulin, A. Karpechko |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 11 ; Nr. 5, no. 11 (2005-11-24), S.3159-3172 |
| Datensatznummer |
250003157
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| Publikation (Nr.) |
 copernicus.org/acp-5-3159-2005.pdf |
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| Zusammenfassung |
| The wintertime ozone buildup over the Northern Hemisphere (NH) midlatitudes
and its connection with the mean meridional circulation in the stratosphere
are examined statistically on a monthly basis from October to March
(1980–2002). The ozone buildup begins locally in October with positive total
ozone tendencies over the North Pacific, which spread eastward and westward
in November and finally cover all midlatitudes in December. The local onset
of the buildup in October is not evident in zonal mean ozone tendency, which
is close to zero. From November to March, zonal mean total ozone tendency
(50°–60° N) shows a strong correlation (|r|=0.7) with several zonal mean
parameters associated to the mean meridional circulation, namely: eddy heat
flux, temperature tendency, the vertical residual velocity and the residual
streamfunction. At the same time, on the latitude-altitude cross section,
correlation patterns between ozone tendency and widely used eddy heat flux
are not uniform during winter. The strongest correlations are located
equatorward (almost throughout the stratosphere) or poleward (only in the
lower stratosphere) of the edge of the polar vortex. Such distribution may
depend on the existence of the midlatitude and polar waveguides which
defined refraction of upward propagating waves from the troposphere either
to the midlatitude stratosphere or to the polar stratosphere. As a
consequence of the nonuniform correlation patterns, heat flux averaged over
the common region 45°–75° N, 100 hPa is not always an optimum proxy
for statistical models describing total ozone variability in midlatitudes.
Other parameters approximating the strength of the mean meridional
circulation have more uniform and stable correlation patterns with ozone
tendency during winter. We show that the NH midlatitude ozone buildup has a
stable statistical relationship with the mean meridional circulation in all
months from October to March and half of the interannual variability in
monthly ozone tendencies can be explained by applying different proxies of
the mean meridional circulation. |
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