Vicinity Of Critical Layer Research Articles

Behavior of gravity waves with limited amplitude in the vi-cinity of critical layer

By using the FICE scheme, a numerical simulation of three-dimensional nonlinear propagation of gravity wave packet in a wind-stratified atmosphere is presented. The whole nonlinear propagation process of the gravity wave packet is shown; the propagation behavior of gravity waves in the vicinity of critical layer is analyzed. The results show that gravity waves encounter the critical layer when propagating in the fair winds whose velocities increase with height, and the height of critical layer propagating nonlinearly is lower than that expected by the linear gravity waves theory; the amplitudes of gravity waves increase with height as a whole before gravity waves encounter the critical layer, but the increasing extent is smaller than the result given by the linear theory of gravity waves, while the amplitudes of gravity waves reduce when gravity waves meet the critical layer; the energy of wave decreases with height, especially at the critical layer; the vertical wavelength reduces with the height increasing, but it does not become zero.

EFFECT OF RELATIVISTIC HYSTERESIS ON RESONANCE ABSORPTION

Using a simple model, it is shown that because of the relativistic electron-mass variation, the mode-converted electrostatic electric field exhibits hysteresis in the vicinity of critical layer. This hysteretic effect is to increase the resonance absorption of obliquely incident p-pola-rized light in a way by increasing the large amplitude region of the electrostatic field. When the threshold light intensity for the occurance of hysteresis is exceeded, the fractional absorption increases drastically above the linear results.