A waving action with strong up and down motions started as air moves across mountain ranges.

A waving action with strong up and down motions started as air moves across mountain ranges.

• A. Soaring
• B. Wave
• C. Stability
• D. Lapse rate

Answer: (B)

When air flowing over mountains forms a repeating vertical motion pattern downstream, it’s describing a wave in the atmosphere. Mountains disturb the flow, and if the air is relatively stable, gravity pulls the air back down after it is lifted, creating alternating updrafts and downdrafts that travel away from the terrain. This wave pattern is known as a mountain or lee wave, and the key idea is the wave-like disturbance produced by airflow over terrain. So the best match for “a waving action with strong up and down motions started as air moves across mountain ranges” is Wave. The other terms don’t fit the described motion: soaring relates to using rising air for lift, stability is about how resistant the air is to vertical motion, and lapse rate is the rate of temperature change with height, none of which capture the actual wave, oscillating motion caused by the mountains.

When air flowing over mountains forms a repeating vertical motion pattern downstream, it’s describing a wave in the atmosphere. Mountains disturb the flow, and if the air is relatively stable, gravity pulls the air back down after it is lifted, creating alternating updrafts and downdrafts that travel away from the terrain. This wave pattern is known as a mountain or lee wave, and the key idea is the wave-like disturbance produced by airflow over terrain. So the best match for “a waving action with strong up and down motions started as air moves across mountain ranges” is Wave.

The other terms don’t fit the described motion: soaring relates to using rising air for lift, stability is about how resistant the air is to vertical motion, and lapse rate is the rate of temperature change with height, none of which capture the actual wave, oscillating motion caused by the mountains.