The wind over the surface of the Earth is an example of what?

• A. A scalar field
• B. A vector field
• C. A tensor field
• D. A scalar and vector field

Answer: (B)

Wind is described by a velocity at every point, which includes both how fast the air is moving and which direction it’s moving in. That combination of magnitude and direction makes it a vector field. A scalar field would only assign a single number to each point (like temperature or pressure) with no direction, and a tensor field involves more complex quantities beyond a simple velocity vector. So the wind over the Earth's surface forms a vector field (even when we focus on the horizontal components on the map).