Which phenomenon describes a rotating column of air that does not touch the ground?

A rotating column of air that does not touch the ground is best described as a funnel cloud. This term refers specifically to the cloud formation that occurs in association with severe thunderstorms, where the rotating air becomes visible as a funnel-shaped cloud.

Funnel clouds are important to identify because they can potentially develop into tornadoes if they make contact with the ground. The distinction lies in the fact that a funnel cloud is a precursor to a tornado and is characterized by its rotation and vertical orientation.

In contrast, duststorms and sandstorms involve suspended particles and can create significant visibility issues but do not specifically relate to a rotating column of air. A squall refers to a sudden and intense increase in wind, often accompanied by precipitation, rather than a specific cloud formation. Understanding these distinctions is crucial in meteorology and aviation, especially when interpreting weather conditions and potential hazards.