Which statement best describes the daytime boundary layer near the ground?

Which statement best describes the daytime boundary layer near the ground?

• A. It becomes completely calm
• B. It experiences less turbulence
• C. It experiences more turbulence due to heating
• D. It is unaffected

Answer: (C)

During daytime, the sun heats the ground, warming the air right above it. This heated air becomes buoyant and rises, creating thermals and strong vertical mixing. That buoyancy-driven motion increases turbulence near the surface, so the boundary layer becomes more chaotic and gusty as the day grows. In contrast, completely calm conditions or less turbulence would require stable air with little vertical mixing, which daytime heating typically disrupts. And the boundary layer is not unaffected—the surface and solar heating actively drive its behavior. So the daytime boundary layer near the ground experiences more turbulence due to heating.

During daytime, the sun heats the ground, warming the air right above it. This heated air becomes buoyant and rises, creating thermals and strong vertical mixing. That buoyancy-driven motion increases turbulence near the surface, so the boundary layer becomes more chaotic and gusty as the day grows. In contrast, completely calm conditions or less turbulence would require stable air with little vertical mixing, which daytime heating typically disrupts. And the boundary layer is not unaffected—the surface and solar heating actively drive its behavior. So the daytime boundary layer near the ground experiences more turbulence due to heating.