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| Titel |
On the possible causes of recent increases in northern hemispheric total ozone from a statistical analysis of satellite data from 1979 to 2003 |
| VerfasserIn |
S. Dhomse, M. Weber, I. Wohltmann, M. Rex, J. P. Burrows |
| 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 ; 6, no. 5 ; Nr. 6, no. 5 (2006-04-13), S.1165-1180 |
| Datensatznummer |
250003721
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| Publikation (Nr.) |
 copernicus.org/acp-6-1165-2006.pdf |
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| Zusammenfassung |
| Global total ozone measurements from various satellite instruments
such as SBUV, TOMS, and GOME show an increase in zonal mean total
ozone at northern hemispheric (NH) mid to high latitudes since the
mid-nineties. This increase could be expected from the peaking and
start of decline in the effective stratospheric halogen loading, but
the rather rapid increase observed in NH zonal mean total ozone
suggests that another physical mechanism such as winter planetary
wave activity has increased which has led to higher stratospheric
Arctic temperatures. This has enhanced ozone transport into higher
latitudes in recent years as part of the residual circulation and at
the same time reduced the frequency of cold Arctic winters with
enhanced polar ozone loss. Results from various multi-variate linear
regression analyses using SBUV V8 total ozone with explanatory
variables such as a linear trend or, alternatively, EESC (equivalent
effective stratospheric chlorine) and on the other hand planetary
wave driving (eddy heat flux) or, alternatively, polar ozone loss
(PSC volume) in addition to proxies for stratospheric aerosol
loading, QBO, and solar cycle, all considered to be main drivers for
ozone variability, are presented. It is shown that the main
contribution to the recent increase in NH total ozone is from the
combined effect of rising tropospheric driven planetary wave
activity associated with reduced polar ozone loss at high latitudes
as well as increasing solar activity. This conclusion can be drawn
regardless of the use of linear trend or EESC terms in our
statistical model. It is also clear that more years of data will be
needed to further improve our estimates of the relative
contributions of the individual processes to decadal ozone
variability. The question remains if the observed increase in
planetary wave driving is part of natural decadal atmospheric
variability or will persist. If the latter is the case, it could be
interpreted as a possible signature of climate change. |
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