DISPERSIVE THEORY AND NUMERICAL COMPUTATION OF THE ACOUSTIC-GRAVITY WAVE IN TWO-LAYER MODEL

Based on the two-layer model suggested by Pekeris¹, the theory of the dispersion of the acoustic-gravity wave dealing with a constant wind speed in each layer is discussed in this paper.
From the basic wave equations of the acoustic-gravity wave, the confluent hydrogeometrie equation for two-layer model with a constant wind speed is derived, and its general solution are given. Using the continuous condition of vertical velocity of air partical motion and the acoustical pressure on the boundary between the two layers, and using the stiff condition on the ground, the dispersive equation is obtained. And the analystical representations of the phase and group velocities are given too.
The methods of the computation are detailed. The results of the numerical calculation on computer represent that the wihd speeds greatly affect the propagation of the acoustic-gravity wave. The phase and group velocities depend on the wind speeds in the two layers. The excited cutoff frequency of the acoustic-gravity wave is also influenced by the wind speed, and it varies greatly for different wind speeds.