THE NONLINEAR PROPAGATION OF GRAVITY WAVE PACKETS IN DISSIPTIVE ATMOSPHERE

For elucidating the effect of dissipation on the nonlinear propagation of gravitywave-packet, a numerical simulation of nonlinear propagation of a Gaussian gravitywave-packet in a dissipative atmosphere is carried out and compared with that in a nondissipative atmosphere. The numerical analysis shows that for an initially given upgoing gravity-wave-packet, although there exists the joint action of nonlinear interaction and dissipation during the propagation, the whole wave packet and the wave-associated energy keep moving upward. Wave-associated perturbation velocity increases with the increasing height, but the increased perturbation velocity is much less than that in the nondissipative case, on the other hand, the ambient shows an obvious enhancement. The wave-associated energy decreases monotonously with time. The propagation path and velocity of wave-associated energy coincides well with those in the nondissipative case. These indicate that when a gravity-wave-packet propagates in a dissipative atmosphere, there is no obvious effects of dissipation on the energy propagation of gravity wave. The dissipation can only restrict the increment of the disturbance velocity and transmit the wave energy to the ambient.