Social science, Geography, chapter 4 air around us

1. CHAPTER 4
AIR AROUND US
By Kamlesh Khanna

3. IN THE ABSENCE OF AIR
❖The earth would remain frozen
❖Lifeless planet in space like any other planet
Atmosphere is the result of :
⮚Gradual and continuous changes ( 4600 million
ago)
⮚That were energised by the Sun

5. STRUCTURE OF THE ATMOSPHERE

7. TROPOSPHERE

8. LAYERS OF ATMOSPHERE

10. STRATOSPHERE

11. OZONE LAYER
❖Special form of oxygen
❖It acts as a shield over the earth surface
❖It act as a filter and absorbs harmful ultraviolet
sun rays from reaching the earth surface
❖Ultraviolet rays of the sun can cause skin
cancer and different kinds of allergies

13. MESOSPHERE

15. THERMOSPHERE

17. AIR AND ITS COMPOSITION

18. IMPORTANCE OF GASES
NITROGEN
• it occupies 78% of the total volume in the air .
• Plants absorb nitrogen through soil
• Used by plants to support their growth and development.
Oxygen
• it occupies 21% of the total volume in the air
• All living organism inhale oxygen from the surrounding air
• It is known as life supporting gas

19. CARBON DI OXIDE
It constitutes a very small percentage ie. 0.03% of the air. Maintaining life
cycle of the plants over the Earth .
GLOBAL WARMING
• Global warming is threatening the life support system of the earth.
• It can be prevented by minimising the use of CO2, CFCs, Methane etc.
• Other gases like argon, helium, methane etc. in small volume .
• Water vapour and dust particles are other important components present in
the atmosphere.

20. POLLUTANTS IN THE AIR
Activity
Playing automobiles
Smoke particles
Volcanic eruption
(some countries)
Forest fire
Release
s
gaseous pollutants like
carbon mono oxide
combined with fog
form smog
solid and gaseous
substances
damage the
atmosphere
Causing
several diseases
serious health
problem (irritation in
eyes, skin disease,
respiratory disease)

21. ATMOSPHERIC TEMP. & PRESSURE
The pressure / weight of air
is measured by an
instrument called
barometer
unit- millibar
normal air pressure at sea
level 1013 millibar

22. WIND
Flow or movement of air
is called wind Windvane
wind flows HP - LP
example :phenomenon of
monsoon

23. MECHANISM OF RAINFALL

24. RAIN GAUGE

25. WEATHER

26. CLIMATE