What causes wind?

What causes wind?

• A. The rotation of the Earth on its axis
• B. Differences in air pressure caused by uneven heating of Earth's surface
• C. The gravitational pull of the Moon
• D. Solar flares in space

Answer: (B)

Wind happens because air moves from places with higher pressure to places with lower pressure. Those pressure differences come from uneven heating of Earth's surface. When the sun warms some areas more than others, the air near the ground becomes warmer and lighter and tends to rise, lowering the surface pressure in that area. Cooler, denser air then moves in to fill the space, creating wind. The strength of the wind grows with the size of the pressure difference. Local winds, like day–night breezes, come from this same idea: land heats up and cools down faster than the sea, so pressure over land changes more quickly and air moves toward or away from the land–sea boundary. On a larger scale, global wind patterns form from intense heating near the equator and cooler air elsewhere, with the Earth’s rotation later shaping their paths through the Coriolis effect. The other options don’t explain why air moves: the Moon’s gravity drives tides, solar flares don’t drive atmosphere wind, and while the Earth’s rotation affects wind direction, it isn’t the cause of wind itself.

Wind happens because air moves from places with higher pressure to places with lower pressure. Those pressure differences come from uneven heating of Earth's surface. When the sun warms some areas more than others, the air near the ground becomes warmer and lighter and tends to rise, lowering the surface pressure in that area. Cooler, denser air then moves in to fill the space, creating wind. The strength of the wind grows with the size of the pressure difference.

Local winds, like day–night breezes, come from this same idea: land heats up and cools down faster than the sea, so pressure over land changes more quickly and air moves toward or away from the land–sea boundary. On a larger scale, global wind patterns form from intense heating near the equator and cooler air elsewhere, with the Earth’s rotation later shaping their paths through the Coriolis effect.

The other options don’t explain why air moves: the Moon’s gravity drives tides, solar flares don’t drive atmosphere wind, and while the Earth’s rotation affects wind direction, it isn’t the cause of wind itself.