Factors Affecting speed and direction of Winds are Pressure gradient force, frictional force & coriolis force. The pressure gradient is the rate of change of pressure with respect to distance. Wind movement is caused by the Pressure Gradient Force, which operates from a high-pressure area to a low-pressure area.
Relationship Between Pressure Gradient And Air Circulation
- The variation in barometric pressure over a certain distance is known as the pressure gradient.
- High wind speeds are associated with large changes in pressure over short distances, whereas lower or non-existent winds are associated with settings with less change in pressure over long distances.
- This is because, in order to achieve balance within the atmosphere, higher-pressure air always travels toward lower-pressure air.
- A stronger push is produced by steeper gradients.
Factors Affecting the Movement of Winds
- The wind is the term for moving air.
- The wind changes direction from high to low pressure.
- At the surface, the wind encounters friction.
- The wind is also affected by the earth’s rotation.
- The Coriolis force is the force exerted by the rotation of the earth.
- As a result, the horizontal winds near the Earth’s surface are influenced by three forces:
- The Pressure Gradient Force
- The Frictional Force
- The Coriolis Force
(A) The Pressure Gradient Force
- 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.
(B) The Frictional Force
- It impacts the speed of the wind.
- The friction is maximum at the surface and minimal over the sea surface.
- The influence of frictional force usually stretches up to an elevation of 1 – 3 km.
(C) The 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.
- Demonstrated by Gaspaved de Coriolis in 1844 and known as the Coriolis effect or coriolis force.
- Coriolis force tend 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 (see fig.) This is known as Ferrel’s law.
- The Coriolis force is absent along the equator but increases progressively towards the poles.
- As the wind is generated by changes in pressure, it’s vital to examine pressure gradients.
- The speed with which the wind goes from higher to lower pressure is determined by the strength of the pressure gradient.
Forces affecting Winds : Speed & Direction,Forces affecting Winds : Speed & Direction,Forces affecting Winds : Speed & Direction
Read more : Wind Movement