Accession Number : ADA181414

Title :   Long Nonlinear Waves in the Lower Atmosphere.

Descriptive Note : Final scientific rept. for period ending 31 Dec 85,

Corporate Author : AUSTRALIAN NATIONAL UNIV CANBERRA RESEARCH SCHOOL OF EARTH SCIENCES

Personal Author(s) : Christie,Douglas R

PDF Url : ADA181414

Report Date : 06 May 1987

Pagination or Media Count : 82

Abstract : A general theoretical treatment of long nonlinear wave propagation in the lower atmosphere is presented. The eigenvalue problem for finite-amplitude wave in a surface-based inversion is discussed in detail and expressions are obtained in closed form for the nonlinear wave parameters, surface perturbation pressure and wind components for a number of realistic boundary-layer waveguide models. The governing evolution equations for wave amplitude have been solved numerically for a wide variety of initial conditions and the results are found to compare favourably with observations. Nonlinear wave propagation in an inhomogeneous waveguide is also studied in detail. It is shown that both temporal and spatial variations in the degree of turbulent dissipation can induce significant changes in the speed of propagation and in the morphology of boundary-layer nonlinear wave disturbances. Keywords: Solitary atmospheric waves; Long nonlinear waves; Internal bore waves.

Descriptors :   *INTERNAL WAVES, *ATMOSPHERE MODELS, ATMOSPHERES, WAVE PROPAGATION, BOUNDARY LAYER, MODELS, WAVEGUIDES, EIGENVALUES, AUSTRALIA, BORES, LOW ALTITUDE, NONLINEAR PROPAGATION ANALYSIS, NONLINEAR SYSTEMS, WAVES, DISSIPATION, TURBULENCE, EQUATIONS, EVOLUTION(GENERAL), EARTH ATMOSPHERE, LONG WAVELENGTHS, NONLINEAR ANALYSIS, PARAMETERS, SPATIAL DISTRIBUTION, VELOCITY, GROUND LEVEL, PROPAGATION, INVERSION, TROPOSPHERE, WIND, PERTURBATIONS, PRESSURE, SURFACE PROPERTIES, AMPLITUDE, AUSTRALIA, EARTH ATMOSPHERE, TROPOSPHERE

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE