What phenomenon describes a waving action with strong up and down motions as air moves across mountain ranges?

The phenomenon that describes a waving action with strong up and down motions as air moves across mountain ranges is best characterized by the term "wave." This term refers to the formation of mountain waves, which occur when stable air flows over irregular terrain, such as mountains. As the air encounters the mountain, it is forced upward, creating a rising motion, and once it goes over the peak, it descends, leading to alternating regions of rising and sinking air. This can produce strong vertical currents, which can significantly impact weather patterns and aviation activities.

The other options represent different atmospheric phenomena. Surge typically refers to a sudden, strong movement of air, often linked to severe weather but does not specifically describe the oscillatory wave pattern over mountains. Thermal refers to localized columns of rising air caused by uneven heating of the Earth's surface, which is not specifically related to mountains. Wind shear describes a change in wind speed or direction with altitude, which can lead to turbulence, but does not directly describe the wave action characteristic of airflow over mountain ranges.