Which of the following conditions contributes to a change in wind direction in the friction layer?

The change in wind direction in the friction layer is significantly influenced by surface drag from rough terrain. As wind interacts with various surfaces such as forests, buildings, or uneven landscape, it experiences friction. This friction slows down the wind, causing it to alter its direction compared to the wind above the friction layer where drag is minimal. As the terrain becomes more rugged or obstructive, the greater the impact on the wind’s flow patterns due to this drag, leading to a noticeable change in direction at lower altitudes.

This phenomenon is especially important for pilots and meteorologists, as understanding the effects of the surface on wind direction helps in predicting local weather conditions and ensuring safe flight operations. When winds move from a uniform, smoother flow aloft to the turbulent and variable conditions closer to the Earth's surface, the friction layer becomes crucial in determining how the wind behaves.