What effect does friction have on wind speed?

Friction plays a significant role in the behavior of wind, particularly near the Earth's surface. As wind moves over the ground, it encounters various forms of surface roughness such as trees, buildings, and terrain irregularities. This interaction causes a drag effect, which effectively reduces the wind speed.

Additionally, friction influences the Coriolis Force, which is responsible for the deflection of wind due to the Earth's rotation. When friction slows down the wind, it alters the balance between the horizontal pressure gradient force and the Coriolis Force. Since the Coriolis effect is dependent on wind speed—stronger winds lead to a greater deflection—reducing wind speed also diminishes the impact of the Coriolis force.

Thus, friction not only decreases wind speed but also reduces the Coriolis effect, affecting the overall dynamics of wind patterns in the lower atmosphere. This understanding is essential for explaining how surface conditions can impact weather systems.