Where are rotor clouds typically found?

Rotor clouds are typically formed as a result of airflow over mountain ranges, where the wind encounters obstacles and generates waves in the atmosphere. These clouds are associated with the turbulent air patterns that occur downwind of mountain wave systems.

When the wind flows over a mountain, it creates a series of oscillating waves. As the air ascends and then descends, it can generate strong updrafts and downdrafts, leading to the formation of rotor clouds. These clouds are found at lower altitudes in the turbulent zone that occurs just beneath and downwind of the crest of the mountain waves. The presence of rotor clouds indicates turbulent conditions that can pose challenges for pilots.

The other locations mentioned in the question do not align with where rotor clouds are typically observed. Calm seas do not produce the necessary airflow disturbances, mountainous areas alone do not guarantee the specific conditions for rotor clouds, and while high altitudes may be involved in wave phenomena, rotor clouds are specifically noted for their association with the turbulent air areas close to the mountains, particularly downwind of the wave crests.