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| Titel |
Spectral energy transfer of atmospheric gravity waves through sum and difference nonlinear interactions |
| VerfasserIn |
K. M. Huang, A. Z. Liu, S. D. Zhang, F. Yi, Z. Li |
| 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 ; 30, no. 2 ; Nr. 30, no. 2 (2012-02-03), S.303-315 |
| Datensatznummer |
250017180
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| Publikation (Nr.) |
 copernicus.org/angeo-30-303-2012.pdf |
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| Zusammenfassung |
| Nonlinear interactions of gravity waves are studied with
a two-dimensional, fully nonlinear model. The energy exchanges among resonant
and near-resonant triads are examined in order to understand the spectral
energy transfer through interactions. The results show that in both resonant
and near-resonant interactions, the energy exchange between two high
frequency waves is strong, but the energy transfer from large to small
vertical scale waves is rather weak. This suggests that the energy cascade
toward large vertical wavenumbers through nonlinear interaction is
inefficient, which is different from the rapid turbulence cascade. Because
of considerable energy exchange, nonlinear interactions can effectively
spread high frequency spectrum, and play a significant role in limiting wave
amplitude growth and transferring energy into higher altitudes. In resonant
interaction, the interacting waves obey the resonant matching conditions,
and resonant excitation is reversible, while near-resonant excitation is not
so. Although near-resonant interaction shows the complexity of match
relation, numerical experiments show an interesting result that when sum and
difference near-resonant interactions occur between high and low frequency
waves, the wave vectors tend to approximately match in horizontal direction,
and the frequency of the excited waves is also close to the matching value. |
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