4.3.2. Coriolis Force

Winds do not cross the isobars at right angles as the pressure gradient directs them. They get deflected from their original paths. One of the most potent influences on wind direction is the deflection caused by the earth’s rotation on its axis. This deflection is always to the right of the direction of motion in the northern hemisphere and to the left in the southern hemisphere (figure 15(b)). This influence is known as Coriolis force.

(a) Relationship between pressure (b) Coriolis force under action gradient and speed of winds