1. WEATHER AND CLIMATE
PRESSURE AND WIND

2. ATMOSPHERIC PRESSURE
 It is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of Earth.

3. WIND
It consists of the movement of the air.

4. WORL PRESSURE SYSTEM
Equator´s zone is heated by the Sun, warming its air, that tends to rise. So a HIGH PRESSURES BELT is created, it is also the INTERTROPICAL CONVERGENCE ZONE (ITC), because the winds from north and south converge there.

5. WORL PRESSURE SYSTEM
On the other hand, Poles´zones are cold because of the Sun, so their air is more dense. The atmospheric pressure is higher than normal. On Poles we find a HIGH PRESSURE ZONE or DEPRESSION.

6. WORL PRESSURE SYSTEM
The difference of pressure and temperature between the Equator and Poles creates movements of the air (horizontal and vertical).
World pressure system without Rotation Movement.

7. CORIOLIS EFFECT
But the Earth is moving on its axis, and Rotation causes CORIOLIS EFFECT.

8. WORL PRESSURE SYSTEM
Due to Coriolis Effect in the Northern Hemisphere the wind flow around high pressure systems to go clockwise while flow around low-pressure systems travels counterclockwise.
 In the Southern Hemisphere, the opposite takes place: Wind around low-pressure systems circles clockwise while wind around high-pressure systems circles counterclockwise.

9. WORLD PRESSURE SYSTEM

10. WORLD PRESSURE SYSTEM

11. WORLD PRESSURE SYSTEM

12. EQUATOR (Depressions)
As the air rises (heat up by Sun´s rays), it leaves behind an area of low pressure. Light winds as air flows in from the north and south to fill the area of low pressure.

13. SUB-TROPICAL ZONES (Anticyclons)
Between the Tropics there is a convenction cycle. Where the air heated and forced upwards from the Equator, cools and sinks back to earth.
It forms two high pressure zones (around latitude 30º).
From there the air returns
to the Equator as TRADE
WINDS (alisios).

14. SUB-POLAR ZONES (Depressions)
Between 60º-50º we find a Low pressure belt. Where the warm air mixes with colder air travelling from the polar regions. It is created POLAR FRONT.

15. POLAR REGIONS
Permanently under HIGH PRESSURE, caused by low temperatures.
Warm air from the mid-latitudes travels into polar regions and descends at the poles.

18. INDIAN MONSOON

19. INDIAN MONSOON

20. INDIAN MONSOON

21. INDIAN MONSOON