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Titel |
Extracting gravity wave parameters during the September 2002 Southern Hemisphere major sudden stratospheric warming using a SANAE imaging riometer |
VerfasserIn |
N. Mbatha, V. Sivakumar, H. Bencherif, S. Malinga |
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 ; 31, no. 10 ; Nr. 31, no. 10 (2013-10-15), S.1709-1719 |
Datensatznummer |
250086123
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Publikation (Nr.) |
copernicus.org/angeo-31-1709-2013.pdf |
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Zusammenfassung |
Using absorption data measured by imaging riometer for ionospheric studies
(IRIS) located at the South Africa National Antarctic Expedition (SANAE),
Antarctica (72° S, 3° W), we extracted the parameters of
gravity waves (GW) of periods between 40 and 50 min during late
winter/spring of the year 2002, a period of the unprecedented major sudden
stratospheric warming (SSW) in the Southern Hemisphere middle atmosphere.
During this period, an unprecedented substantial increase of temperature by
about 25–30 K throughout the stratosphere was observed. During the period
of the occurrence of the major stratospheric warming, there was a reduction
of both the GW horizontal phase speeds and the horizontal wavelengths at 90 km.
The GW phase speeds and horizontal wavelengths were observed to reach
minimum values of about 7 m s−1 and 19 km, respectively, while during
the quiet period the average value of the phase speed and horizontal
wavelength was approximately 23 m s−1 and 62 km, respectively. The
observed event is discussed in terms of momentum flux and also a potential
interaction of gravity waves, planetary waves and mean
circulation. |
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