What results in mountain wave turbulence?

Mountain wave turbulence occurs due to strong winds blowing perpendicular to a mountain range. When these winds encounter the mountains, they are forced to rise. As the air flows over the mountain peaks, it can create a series of oscillating waves on the downwind side. This mechanism is similar to a stream flowing over rocks, where turbulence is created in the flow due to the obstruction presented by the terrain.

The vertical displacement of airflow generates turbulence as the air tries to return to its equilibrium state. The strength of this turbulence is influenced by the wind speed and stability of the atmosphere, as well as the height and shape of the mountains.

Winds blowing parallel to a mountain range would not typically create the same kind of upward and downward air currents that result in mountain wave turbulence, as they do not interact with the mountains in a way that creates those oscillations. High altitude weather phenomena and thermal downdrafts pertain to different types of turbulence and are not the primary cause of mountain wave turbulence.