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Titel |
VHF radar observations of gravity waves at a low latitude |
VerfasserIn |
G. Dutta, B. Bapiraju, P. Balasubrahmanyam, H. Aleem Basha |
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 ; 17, no. 8 ; Nr. 17, no. 8, S.1012-1019 |
Datensatznummer |
250013796
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Publikation (Nr.) |
copernicus.org/angeo-17-1012-1999.pdf |
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Zusammenfassung |
Wind observations made at Gadanki (13.5°N)
by using Indian MST Radar for few days in September, October, December 1995 and
January, 1996 have been analyzed to study gravity wave activity in the
troposphere and lower stratosphere. Horizontal wind variances have been computed
for gravity waves of period (2-6) h from the power spectral density (PSD)
spectrum. Exponential curves of the form eZ/H
have been fitted by least squares technique to these variance values to obtain
height variations of the irregular winds upto the height of about 15 km, where Z
is the height in kilometers. The value of H, the scale height, as
determined from curve fitting is found to be less than the theoretical value of
scale height of neutral atmosphere in this region, implying that the waves are
gaining energy during their passage in the troposphere. In other words, it
indicates that the sources of gravity waves are present in the troposphere. The
energy densities of gravity wave fluctuations have been computed. Polynomial
fits to the observed values show that wave energy density increases in the
troposphere, its source region, and then decreases in the lower stratosphere.
Key words. Meteorology and atmospheric dynamics (middle
atmosphere dynamics; turbulence; waves and tides) |
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