Dynamics of nonharmonic internal gravity wave packets in stratified media
Abstract
In the paper taking the assumption of the slowness of the change of the parameters of the vertically stratified medium in the horizontal direction and in time, the evolution of the nonharmonic wave packages of the internal gravity waves has been analyzed. The concrete form of the wave packages can be expressed through some model functions and is defined by the local behavior of the dispersive curves of the separate modes near to the corresponding special points. The solution of this problem is possible with the help of the modified variant of the specialtime ray method offered by the authors (the method of geometrical optics), the basic difference of which consists that the asymptotic representation of the solution may be found in the form the series of the noninteger degrees of some small parameter. At that the exponent depends on the concrete form of representation of this package. The obvious kind of the representation is determined from the principle of the localness and the asymptotic behavior of the solution in the stationary and the horizontallyhomogeneous case. The phases of the wave packages are determined from the corresponding equations of the eikonal, which can be solved numerically on the characteristics (rays). Amplitudes of the wave packages are determined from the laws of conservation of the some invariants along the characteristics (rays).
 Publication:

arXiv eprints
 Pub Date:
 August 2008
 arXiv:
 arXiv:0808.0668
 Bibcode:
 2008arXiv0808.0668B
 Keywords:

 Physics  Fluid Dynamics;
 Physics  Atmospheric and Oceanic Physics
 EPrint:
 6 pages