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| Titel |
The two-day wave in the Antarctic and Arctic mesosphere and lower thermosphere |
| VerfasserIn |
V. M. Tunbridge, N. J. Mitchell |
| 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 ; 9, no. 17 ; Nr. 9, no. 17 (2009-09-03), S.6377-6388 |
| Datensatznummer |
250007606
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| Publikation (Nr.) |
 copernicus.org/acp-9-6377-2009.pdf |
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| Zusammenfassung |
| There have been comparatively few studies reported of the 2-day planetary
wave in the middle atmosphere at polar latitudes. Here we report on a study
made using high-latitude meteor radars at Rothera in the Antarctic (68° S,
68° W) and Esrange in Arctic Sweden (68° N, 21° E).
Observations from 2005–2008 are used for Rothera and from 1999–2008 for
Esrange. Measurements were made of horizontal winds at heights of 80–100 km. The radar data revealed distinct summertime and wintertime 2-day waves. The
Antarctic summertime wave occurs with significant amplitudes in January –
February at heights between about 88–100 km. Horizontal wind monthly
variances associated with the wave exceed 160 m2 s−2 and the zonal
component has larger amplitudes than the meridional. In contrast, the Arctic
summertime wave occurs for a longer duration, June–August and has
meridional amplitudes larger than the zonal amplitudes. The Arctic
summertime wave is weaker than that in the Antarctic and maximum monthly
variances are typically 60 m2 s−2. In both hemispheres the
summertime wave reaches largest amplitudes in the strongly sheared eastward
zonal flow above the zero-wind line and is largely absent in the westward
flow below. The observed differences in the summertime wave are probably due
to the differences in the background zonal winds in the two hemispheres. The
Antarctic and Arctic wintertime 2-day waves have very similar behaviour. The
Antarctic wave has significant amplitudes in May–August and the Arctic
wave in November–February. Both are evident across the full height range
observed. |
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