How is "Wake Turbulence" defined?

Wake turbulence is defined as the disturbance in the air that occurs as a result of an aircraft flying through it. This type of turbulence is specifically generated by the lift produced by an aircraft's wings; as the aircraft takes off or lands, it leaves behind a rotating vortex of air. These vortices descend and drift laterally, creating significant turbulence that can affect trailing aircraft, especially smaller ones. Understanding this phenomenon is critical for maintaining safety in aviation operations, as wake turbulence can lead to loss of control if a following aircraft encounters it unexpectedly.

The other options do not accurately capture the essence of wake turbulence. For instance, turbulence caused by sudden weather changes pertains to atmospheric conditions rather than lift-induced wake. Air currents affecting small aircraft can encompass a broader range of wind phenomena, whereas wake turbulence specifically refers to the effects of an aircraft's passage. Similarly, turbulence due to mountain waves is a distinct atmospheric occurrence related to topography, not directly associated with the wake effect of flying aircraft. Thus, option B precisely captures the definition of wake turbulence in the context of aviation safety.