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Titel |
Verifications of the high-resolution numerical model and polarization relations of atmospheric acoustic-gravity waves |
VerfasserIn |
N. M. Gavrilov, S. P. Kshevetskii, A. V. Koval |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1991-959X
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Digitales Dokument |
URL |
Erschienen |
In: Geoscientific Model Development ; 8, no. 6 ; Nr. 8, no. 6 (2015-06-22), S.1831-1838 |
Datensatznummer |
250116412
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Publikation (Nr.) |
copernicus.org/gmd-8-1831-2015.pdf |
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Zusammenfassung |
Comparisons of amplitudes of wave variations of atmospheric characteristics
obtained using direct numerical simulation models with polarization relations
given by conventional theories of linear acoustic-gravity waves (AGWs) could
be helpful for testing these numerical models. In this study, we performed
high-resolution numerical simulations of nonlinear AGW propagation at
altitudes 0–500 km from a plane wave forcing at the Earth's surface and
compared them with analytical polarization relations of linear AGW theory.
After some transition time te (increasing with altitude) subsequent to
triggering the wave source, the initial wave pulse disappears and the main
spectral components of the wave source dominate. The numbers of numerically
simulated and analytical pairs of AGW parameters, which are equal with
confidence of 95 %, are largest at altitudes 30–60 km at
t > te. At low and high altitudes and at t < te,
numbers of equal pairs are smaller, because of the influence of the lower
boundary conditions, strong dissipation and AGW transience making substantial
inclinations from conditions, assumed in conventional theories of linear
nondissipative stationary AGWs in the free atmosphere. Reasonable agreements
between simulated and analytical wave parameters satisfying the scope of the
limitations of the AGW theory prove the adequacy of the used wave numerical
model. Significant differences between numerical and analytical AGW
parameters reveal circumstances when analytical theories give substantial
errors and numerical simulations of wave fields are required. In addition,
direct numerical AGW simulations may be useful tools for testing simplified
parameterizations of wave effects in the atmosphere. |
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