Air balances the uneven distribution of pressure.
Air moves from high pressure areas to low pressure areas.
Horizontal movement of air in response to difference in pressure is termed as wind.
Vertical moving air is called air current.
Both winds and air currents form the system of circulation in the atmosphere.
 Pressure Gradient and Winds –
There is a close relationship between the pressure and the wind speed.
The greater the difference in air pressure between the two points, the steeper is the pressure gradient and greater is the speed of the wind.
The gentler the pressure gradient slower is the speed of the wind.
 The Coriolis Effect and Wind –
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.
Demonstrated by Gaspaved de Coriolis in 1844 and known as the Coriolis Effect or Coriolis force.
Coriolis force tends to deflect the winds from their original direction.
In northern hemisphere winds are deflected towards their right, and in the southern hemisphere towards their left. This is known as Farrel’s law.
The Coriolis force is absent along the equator but increases progressively towards the poles.