Which phenomenon explains the apparent turning of moving air due to Earth's rotation?

Which phenomenon explains the apparent turning of moving air due to Earth's rotation?

• A. Pressure gradient force
• B. Friction
• C. Coriolis force
• D. Buys Ballot's Law

Answer: (C)

The turning of moving air on Earth is explained by the Coriolis effect, which arises because the planet is rotating beneath the air as it moves. An air parcel that starts moving north or south carries its original east–west speed, but since the surface beneath rotates faster at lower latitudes than at higher latitudes, the parcel's path appears deflected relative to the ground. In the Northern Hemisphere this deflection is to the right, while in the Southern Hemisphere it is to the left. The stronger the wind and the farther from the equator, the larger the deflection; at the equator the effect is zero. In large-scale flow, this deflection helps produce winds that run roughly parallel to lines of constant pressure (isobars) when the pressure gradient force pushes air from high to low pressure. Near the surface, friction slows winds and reduces the Coriolis deflection, causing winds to cross isobars slightly toward lower pressure. Buys Ballot's Law relates to the orientation of pressure patterns and winds but does not explain the turning caused by Earth's rotation itself.

The turning of moving air on Earth is explained by the Coriolis effect, which arises because the planet is rotating beneath the air as it moves. An air parcel that starts moving north or south carries its original east–west speed, but since the surface beneath rotates faster at lower latitudes than at higher latitudes, the parcel's path appears deflected relative to the ground. In the Northern Hemisphere this deflection is to the right, while in the Southern Hemisphere it is to the left. The stronger the wind and the farther from the equator, the larger the deflection; at the equator the effect is zero.

In large-scale flow, this deflection helps produce winds that run roughly parallel to lines of constant pressure (isobars) when the pressure gradient force pushes air from high to low pressure. Near the surface, friction slows winds and reduces the Coriolis deflection, causing winds to cross isobars slightly toward lower pressure. Buys Ballot's Law relates to the orientation of pressure patterns and winds but does not explain the turning caused by Earth's rotation itself.