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| Titel |
Case study of a mesospheric wall event over Ferraz station, Antarctica (62° S) |
| VerfasserIn |
J. V. Bageston, C. M. Wrasse, R. E. Hibbins, P. P. Batista, D. Gobbi, H. Takahashi, V. F. Andrioli, J. Fechine, C. M. Denardini |
| 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 ; 29, no. 1 ; Nr. 29, no. 1 (2011-01-28), S.209-219 |
| Datensatznummer |
250016960
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| Publikation (Nr.) |
 copernicus.org/angeo-29-209-2011.pdf |
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| Zusammenfassung |
| On 16–17 July 2007 during an observational campaign at Comandante
Ferraz Antarctic Station (62° S, 58° W), a
mesospheric wall was observed with an airglow all-sky imager. The wave
appeared like an extensive dark region in the all-sky airglow images, with a
large depletion in the OH emission. Simultaneous mesospheric winds measured
with a MF radar at Rothera station and temperature profiles from SABER
instrument, on board of TIMED satellite, were used to obtain the propagation
condition of the wave. Wind measurements during four days, around the time of
observation of the wave, are presented in order to discuss the type and
consistence of the duct in which this wave was propagating. By using wavelet
analysis and tidal amplitude components we found that 12 and 8 h
components were the most important periodicities around the time interval of
the wave observation. A collocated imaging spectrometer, for mesospheric
temperature measurements, has been operated simultaneously with the all-sky
imager. Direct effects of the mesospheric front have been seen in the
spectrometric measurements, showing an abrupt decrease in both OH intensity
and rotational temperature when the wave front passes overhead. The main
contribution of the present work is the investigation of the type of duct in
which the wall event was propagating. We found evidences for a thermal duct
structure to support the mesospheric wall propagation. This result was
obtained by two types of analysis: (a) the tidal components analysis and
winds filtering (harmonic analysis), and (b) comparison between the terms of
the m2 dispersion relation. |
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