Which of the following is NOT a force that affects the wind?

• A. Buoyancy force
• B. Pressure Gradient Force
• C. Coriolis Force
• D. Surface Friction

Answer: (A)

Winds arise from a horizontal force balance: the pressure gradient force pushes air from high to low pressure, the Coriolis force deflects the moving air due to Earth's rotation, and surface friction slows and turns the flow near the ground. Buoyancy, meanwhile, acts on air parcels in the vertical direction because of density differences, making parcels rise or sink and driving convection and vertical mixing. This vertical force changes how air moves up and down rather than how it moves horizontally. In the equations that describe wind, buoyancy is not part of the horizontal momentum balance; it enters the vertical motion and thermodynamic aspects of the atmosphere. So buoyancy does not directly affect the wind in the same way as the other forces, making it the correct choice.