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Titel |
Impact of the 2009 major sudden stratospheric warming on the composition of the stratosphere |
VerfasserIn |
M. Tao, P. Konopka, F. Ploeger, J.-U. Grooß, R. Müller, C. M. Volk, K. A. Walker, M. Riese |
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 ; 15, no. 15 ; Nr. 15, no. 15 (2015-08-07), S.8695-8715 |
Datensatznummer |
250119950
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Publikation (Nr.) |
copernicus.org/acp-15-8695-2015.pdf |
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Zusammenfassung |
In a case study of a remarkable major sudden stratospheric warming (SSW) during the
boreal winter 2008/09, we investigate how transport and mixing triggered by
this event affected the composition of the entire stratosphere in the Northern
Hemisphere. We simulate this event with the Chemical Lagrangian Model of the
Stratosphere (CLaMS), both with optimized mixing parameters and with no mixing,
i.e. with transport occurring only along the Lagrangian trajectories.
The results are investigated by using tracer–tracer correlations
and by applying the transformed Eulerian-mean formalism.
The CLaMS simulation of N2O and O3, and in particular of
the O3–N2O tracer correlations with optimized mixing parameters, shows
good agreement with the Aura Microwave Limb Sounder (MLS) data.
The spatial distribution of mixing intensity in CLaMS correlates fairly
well with the Eliassen–Palm flux convergence. This correlation illustrates how planetary
waves drive mixing. By comparing simulations with and without mixing,
we find that after the SSW, poleward transport of air increases, not only across the vortex edge but also across
the subtropical transport barrier.
Moreover, the SSW event, at the same time, accelerates polar descent and tropical ascent of
the Brewer–Dobson circulation. The accelerated ascent in the tropics
and descent at high latitudes first occurs in the upper stratosphere and
then propagates downward to the lower stratosphere.
This downward propagation takes over 1 month from the potential temperature
level of 1000 to 400 K. |
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