Lower Atmosphere Gravity Wave Coupling with a Traveling Atmospheric Disturbance in the Thermosphere

The global thermosphere is continually subjected to wave activity that can arise as a result of atmospheric, thermospheric, and ionospheric disturbances. The waves transport mass, momentum, and energy into, out of, and throughout the thermosphere. The waves can be in the form of gravity waves, tides, planetary waves, or traveling atmospheric disturbances. In this study, the propagation and interaction of two wave types were investigated; a gravity wave and a traveling atmospheric disturbance. The gravity wave was excited in the lower atmosphere at mid-latitudes and then propagated upward and northward. Simultaneously, a Traveling Atmospheric Disturbance (TAD) was excited in the northern thermosphere at high latitudes and propagated southward. The two waves then interacted in the mid-latitude thermosphere. The gravity wave and traveling atmospheric disturbance interacted via a superposition of their wave amplitudes, with the gravity wave amplitude tending to be symmetric about zero when outside the influence of the traveling atmospheric disturbance. However, the gravity wave amplitude was non-symmetric when it interacted with the traveling atmospheric disturbance wave perturbations. These and other wave interactions will be presented.