The Coriolis effect is the tendency for any moving body on or above the earth's surface, e.g., an ocean current or an airplane , to drift sideways from its course because of the earth's rotation.

It is the rotation of the Earth that creates the Coriolis effect. This effect is an inertial force first described by the French engineer-mathematician Gustave-Gaspard Coriolis in 1835.

In the northern hemisphere the Coriolis effect causes air moving southward to turn westward... If you are living at the equator southbound air appears to be moving to the west as the Earth turns east. These wind patterns affect the weather and also influence movement of planes and boats.

SEE VIDEO 1

The object does not actually deviate from its path, but it appears to do so because of the rotation of the coordinate system.

Deflection increases as more ground is covered.

SEE VIDEO 2

In summary in the northern hemisphere the Coriolis effect causes deflection is to the right regardless of direction.

In the southern the Coriolis effect causes deflection to the left.

East and west motions along the equation are the only motions not subject to the Coriolis deflections.