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| Titel |
Composite analysis of a major sudden stratospheric warming |
| VerfasserIn |
K. Hocke, M. Lainer, A. Schanz |
| 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 ; 33, no. 6 ; Nr. 33, no. 6 (2015-06-25), S.783-788 |
| Datensatznummer |
250121215
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| Publikation (Nr.) |
 copernicus.org/angeo-33-783-2015.pdf |
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| Zusammenfassung |
| We present the characteristics of a major sudden stratospheric
warming (SSW) by using the composite analysis method and ERA Interim reanalysis
data from 1979 to 2014. The anomalies of the parameters total ozone column
density (TOC), temperature (T), potential vorticity (PV), eastward wind
(u), northward wind (v), vertical wind (w), and geopotential height
(z) are derived with respect to the ERA Interim climatology (mean seasonal
behaviour 1979 to 2014). The composites are calculated by using the time
series of the anomalies and the central dates of 20 major SSWs. Increases of
up to 90 Dobson units are found for polar TOC after the SSW. Polar TOC
remains enhanced until the summer after the major SSW. Precursors of the SSW
are a negative TOC anomaly 3 months before the SSW and enhanced
temperature at 10 hPa at mid-latitudes about 1 month before the SSW.
Eastward wind at 1 hPa is decreased at mid-latitudes about 1 month before the
SSW. The 1 hPa geopotential height level is increased by about 500 m during the
month before the SSW. These features are significant at the 2σ level
for the mean behaviour of the ensemble of the major SSWs. However, knowledge
of these precursors may not lead to a reliable prediction of an individual
SSW since the variability of the individual SSWs and the polar winter
stratosphere is large. |
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