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Nonlinear theory of gravity waves and enhanced diffusion in the atmosphere
Author(s) -
Weinstock J.
Publication year - 1975
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl002i010p00453
Subject(s) - gravity wave , physics , diffusion , amplitude , gravitational wave , atmosphere (unit) , nonlinear system , computational physics , anisotropy , mesosphere , surface gravity , atmospheric wave , mechanics , geophysics , atmospheric sciences , optics , spectral line , meteorology , stratosphere , thermodynamics , astrophysics , quantum mechanics
A nonlinear calculation is made of the saturated (self‐limited) fractional density fluctuation δρ/ρ o of gravity waves. The result is δρ/ρ o = (γ−1)/[1 + 0.4·γ²k z ² H²Δ] ½ , γ = specific heats ratio, k z = vertical wave no., H= scale height, Δ ∞ spectral width of gravity waves. This calculation is based on a method developed for plasma waves. In addition, a calculation is made of the enhancement of atmospheric diffusion by finite amplitude gravity waves. It is shown that such diffusion is very much anisotropic and has the proper magnitude to explain some observations in the mesosphere.