What effect deflects moving air because Earth rotates?

The Coriolis effect deflects moving air because Earth rotates.

Earth’s rotation makes the ground move at different speeds at different latitudes. Air traveling toward the poles carries the eastward speed of its starting latitude, while the surface beneath it moves at another speed. This difference makes the air appear to curve when viewed from Earth.

The deflection is to the right of motion in the Northern Hemisphere and to the left in the Southern Hemisphere. It is strongest near the poles and zero at the equator. The effect does not create wind; pressure differences start the motion, while rotation changes its path.

The Coriolis effect helps organize trade winds, jet streams, and the circulation around large low- and high-pressure systems. It is too weak to determine the direction water drains from an ordinary bathtub.