Atmospheric Circulation
The movement of air in the air is known as atmospheric circulation.
Earth’s atmospheric circulation is an important transfer mechanism for both energy and mass.
The atmospheric circulation, speed and direction of winds are controlled by several forces.
These forces are as follows-
1. Gravitational Force of the Earth
2. The Pressure Gradient Force
3. The Coriolis force
4. The Friction Force
Gravitational Force of the Earth:
The gravitational force of the Earth is equally compressing the atmosphere near the ground world-wide.
Density of air pressure decreases as altitude increases.
The Pressure Gradient Force:
This force drives air from areas of higher pressure to areas of lower pressure that causes wind.
The Coriolis force:
It is a type of deflective force which appears to deflect wind from a straight path in relation to Earth’s rotating surface.
It deflects winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
The Friction Force:
This force drags on the wind as it moves across surfaces.
It decreases with height above the surface.
Its effect extends to a height of about 500m.
Effect of friction force varies with surface texture, wind speed, time of day and year, and atmospheric conditions.
