Mechanical Turbulence is produced by wind shear and obstacles.

Mechanical Turbulence is produced by wind shear and obstacles.

• A. Wind shear alone
• B. Wind shear and obstacles
• C. Solar heating
• D. Humidity differences

Answer: (B)

Mechanical turbulence occurs when air flow is disrupted by surface roughness and obstacles, creating eddies and gusts. Wind shear—changes in wind speed or direction with height—stirs the flow and amplifies those disturbances, while obstacles such as buildings, trees, and terrain break up the air stream and generate wake turbulence. Together, wind shear and obstacles produce the irregular, swirling motion you feel near the ground. Solar heating causes thermal turbulence through buoyant rising air, a different mechanism, and humidity differences don’t by themselves create significant mechanical turbulence.

Mechanical turbulence occurs when air flow is disrupted by surface roughness and obstacles, creating eddies and gusts. Wind shear—changes in wind speed or direction with height—stirs the flow and amplifies those disturbances, while obstacles such as buildings, trees, and terrain break up the air stream and generate wake turbulence. Together, wind shear and obstacles produce the irregular, swirling motion you feel near the ground. Solar heating causes thermal turbulence through buoyant rising air, a different mechanism, and humidity differences don’t by themselves create significant mechanical turbulence.