What is defined as a change in wind direction or speed?

Wind shear is defined as a change in wind direction or speed, particularly over a short distance in the atmosphere. This phenomenon can occur at various altitudes, including near the ground, at cruising altitudes, or even within thunderstorms. Wind shear is significant because it can affect aircraft performance during takeoff and landing, as well as in-flight stability. Pilots must be aware of potential wind shear conditions to ensure safety and make appropriate adjustments to their flight operations.

Understanding the context, air turbulence refers to irregular or violent motion of the air, which can be caused by various factors like terrain, thermal activity, or weather systems, but it is not specifically defined as a change in wind speed or direction. A thermal gradient involves changes in temperature that can influence air density and pressure but doesn't directly relate to wind changes. The Coriolis effect describes how the rotation of the Earth affects the motion of air and water, leading to curved paths rather than straight lines; it does not specifically define a change in wind characteristics.