MODULE - 4 Atmosphere Composition and Structure
The domain of Air on
the Earth
9
Notes
ATMOSPHERE COMPOSITION
AND STRUCTURE
Earth is a unique planet because the life is found only on this planet. The air has a
special place among the conditions necessary for life. The air is a mixture of sev-
eral gases. The air encompasses the earth from all sides. The air surrounding the
Earth is called the atmosphere. The atmosphere is an integral part of our Earth. It
is connected with the earth due to the gravitational force of the earth. It helps in
stopping the ultra violet rays harmful for the life and maintain the suitable tempera-
ture necessary for life.
The air is essential for the survival of all forms of life on the earth. You cannot
imagine any kind of life in the absence of it. The atmosphere is like a large protective
cover. Besides many gases, water vapour and dust particles are also found in the
atmosphere. Due to these all kinds of changes take place in the atmosphere you
will study in this lesson. The composition and structure of the atmosphere and the
cyclic process of main gases.
OBJECTIVES
After studying this lesson, you will be able to :-
explain the composition of atmosphere.
tell the characteristics of different layers of the atmosphere.
explain the importance of atmosphere.
explain the cyclic process of main gases of the atmosphere – nitrogen, oxygen
and Carbon dioxide.
describe the importance of cyclic process of important gases of the atmosphere
such as nitrogen, oxygen and carbon dioxide.
164 GEOGRAPHY
, Atmosphere Composition and Structure MODULE - 4
The domain of Air on
9.1 COMPOSITION OF ATMOSPHERE the Earth
The atmosphere is made up of different types of gases, water rapour and dust
particles. The composition of the atmosphere is not static. It changes according to
the time and place.
(A) Gases of the atmosphere: Notes
The atmosphere is the mixture of different types of gases, including water
vapour and dust particles. Nitrogen and Oxygen are the two main gases of
the atmosphere. 99 percent part of it is made up of these two gases. Other
gases like organ, carbon dioxide, hydrogen, nion, helium etc. form the
remaining part of atmosphere. The details of different gases of the atmosphere
are given in the table No. 9.1 and Fig. No. 9.1
Table 9.1 : Amount of gases in the dry and
air of the atmosphere.
Serial No. Gas Amount (in percentage)
A. Main
1. Nitrogen 78.1
99%
2. Oxygen 20.9
B. Secondary
1. Organ 0.9
2. Carbon Dioxide 0.03
3. Hydrogen 0.01
0.99%
4. Nion 0.0018
5. Helium 0.0005
6. Ozone 0.00006
7. Others
Fig. 9.1 Composition of Atmosphere
GEOGRAPHY 165
The domain of Air on
the Earth
9
Notes
ATMOSPHERE COMPOSITION
AND STRUCTURE
Earth is a unique planet because the life is found only on this planet. The air has a
special place among the conditions necessary for life. The air is a mixture of sev-
eral gases. The air encompasses the earth from all sides. The air surrounding the
Earth is called the atmosphere. The atmosphere is an integral part of our Earth. It
is connected with the earth due to the gravitational force of the earth. It helps in
stopping the ultra violet rays harmful for the life and maintain the suitable tempera-
ture necessary for life.
The air is essential for the survival of all forms of life on the earth. You cannot
imagine any kind of life in the absence of it. The atmosphere is like a large protective
cover. Besides many gases, water vapour and dust particles are also found in the
atmosphere. Due to these all kinds of changes take place in the atmosphere you
will study in this lesson. The composition and structure of the atmosphere and the
cyclic process of main gases.
OBJECTIVES
After studying this lesson, you will be able to :-
explain the composition of atmosphere.
tell the characteristics of different layers of the atmosphere.
explain the importance of atmosphere.
explain the cyclic process of main gases of the atmosphere – nitrogen, oxygen
and Carbon dioxide.
describe the importance of cyclic process of important gases of the atmosphere
such as nitrogen, oxygen and carbon dioxide.
164 GEOGRAPHY
, Atmosphere Composition and Structure MODULE - 4
The domain of Air on
9.1 COMPOSITION OF ATMOSPHERE the Earth
The atmosphere is made up of different types of gases, water rapour and dust
particles. The composition of the atmosphere is not static. It changes according to
the time and place.
(A) Gases of the atmosphere: Notes
The atmosphere is the mixture of different types of gases, including water
vapour and dust particles. Nitrogen and Oxygen are the two main gases of
the atmosphere. 99 percent part of it is made up of these two gases. Other
gases like organ, carbon dioxide, hydrogen, nion, helium etc. form the
remaining part of atmosphere. The details of different gases of the atmosphere
are given in the table No. 9.1 and Fig. No. 9.1
Table 9.1 : Amount of gases in the dry and
air of the atmosphere.
Serial No. Gas Amount (in percentage)
A. Main
1. Nitrogen 78.1
99%
2. Oxygen 20.9
B. Secondary
1. Organ 0.9
2. Carbon Dioxide 0.03
3. Hydrogen 0.01
0.99%
4. Nion 0.0018
5. Helium 0.0005
6. Ozone 0.00006
7. Others
Fig. 9.1 Composition of Atmosphere
GEOGRAPHY 165
