●  The rotation of the earth about its axis affects the direction of the wind and this force is called the Coriolis force. It is directly proportional to the angle of latitude. It deflects the wind to the left direction in the southern hemisphere and the right direction in the northern hemisphere.

•   The Horizontal movement of the air is called wind. Due to horizontal differences in air pressure, air flows from areas of high pressure to areas of low pressure.

•   Since the direction of the force is from a higher to lower pressure area and perpendicular to the isobars, the initial tendency of the wind is to blow parallel to the gradient and at right angles to the isobars.

•   Due to the rotation of the earth, winds do not cross the isobars at right angles as the pressure gradient force directs but get deflected from their original path.

•   This deviation is the result of the earth's rotation and is called the Coriolis effect or Coriolis force.

•   Due to this effect winds in the northern hemisphere get deflected to the right of their path i.e., in the clockwise direction while it gets deflected to left in the southern hemisphere i.e., in the anti-clockwise direction.

•   The Coriolis force changes the direction of the wind but not its speed.

•   It is noteworthy that this deflection force does not seem to exist until the air is set in motion and it increases as the wind speed increases.