What causes turbulence during a flight?

Turbulence during a flight is primarily caused by any instability in the atmosphere. This instability can arise from various factors, including changes in wind speed and direction, temperature gradients, and atmospheric pressure differences. The atmosphere is constantly in motion, and when layers of air move at different speeds or in different directions, it creates turbulence.

Weather conditions, such as thunderstorms, jet streams, and frontal boundaries, are significant sources of atmospheric instability. This can lead to bumpy flight conditions as the aircraft encounters these variations in airflow. Understanding this helps pilots and crew anticipate and manage turbulence effectively to ensure passenger safety and comfort.

The other options—heavy rainfall, airplane speed, and passenger movement—do not directly cause turbulence in the same way that atmospheric instability does. While adverse weather can contribute to turbulence, it is the instability that is the fundamental cause. Airplane speed may affect how a plane interacts with turbulence but does not create it; passenger movement is irrelevant to atmospheric conditions and turbulence generation.