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| Titel |
Statistical characteristics of AGW wave packet propagation in the lower atmosphere observed by the MU radar |
| VerfasserIn |
F. S. Kuo, H. Y. Lue, C. L. Fern, J. Röttger, S. Fukao, M. Yamamoto |
| 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 ; 27, no. 10 ; Nr. 27, no. 10 (2009-10-02), S.3737-3753 |
| Datensatznummer |
250016665
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| Publikation (Nr.) |
 copernicus.org/angeo-27-3737-2009.pdf |
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| Zusammenfassung |
| We study the horizontal structure of the atmospheric gravity waves
(AGW) in the height ranges between 6 and 22 km observed using the
MU radar at Shigaraki in Japan, during a 3 day period in January and
a 4 day period in August 1988. The data were divided by double
Fourier transformation into a data set of upward moving waves and a
data set of downward moving waves for independent analysis. The
phase and group velocity tracing technique was applied to measure
the vertical group and phase velocity as well as the characteristic
period of the gravity wave packet. Then the dispersion equation of
the linear theory of AGW was solved to obtain its intrinsic wave
period – horizontal wavelength and horizontal group velocity – and
the vertical flux of horizontal momentum associated with each wave
packet was estimated to help determine the direction of the
characteristic horizontal wave vector. The results showed that the
waves with periods in the range of 30 min~6 h had horizontal
scales ranging from 20 km to 1500 km, vertical scales from 4 km
to 15 km, and horizontal phase velocities from 15 m/s to 60 m/s.
The upward moving wave packets of wave period of 2 h~6 h had
horizontal group velocities mainly toward east-south-east and
northeast in winter, and mainly in the section between the
directions of west-north-west and north in summer. |
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