What describes rough air caused by warm air rising and cold air descending?

The correct answer is turbulence, which refers to the chaotic and irregular motion of air. This phenomenon can occur due to thermal currents, where warm air rises and cold air sinks, causing fluctuations in the air around it. These mixed thermal currents create a bumpy, uneven ride for aircraft, commonly referred to as turbulence.

In aviation, turbulence is significant because it can affect the comfort and safety of a flight. Pilots receive training to recognize and manage turbulence, ensuring that they can maintain control of the aircraft and keep passengers safe during these conditions.

While the other terms relate to specific aspects of weather or flight conditions, they do not accurately describe the scenario presented. Wind shear refers to a sudden change in wind speed or direction, which is different from the thermal-induced movements mentioned. A crosswind describes wind blowing perpendicular to the aircraft's flight path, affecting takeoff and landing, but not the rising and descending air caused by temperature differences. Draft typically refers to a local updraft or downdraft in the air but is less comprehensive in explaining the broader effects of turbulence caused by warm and cold air interactions.