Atmosphere
Introduction
The thick layer of air surrounding the earth is called
atmosphere. The atmosphere is divided into five layers. They are:
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
5. Exosphere
Troposphere: It is the lowermost layer of the atmosphere. It lies up to 16 km up from the surface of the earth. This layer lies nearest to the surface of the earth. The topmost layer of troposphere is called the tropopause. It separates the troposphere and stratosphere. Its average temperature is -56oC.
Mesosphere: The layer of
atmosphere between stratosphere and thermosphere is known as mesosphere. It
lies between 50- 80 km from the surface of the earth.
Thermosphere: The layer of
atmosphere which lies between mesosphere and exosphere is called thermosphere.
It lies in the altitude of 80 – 720 km from the surface of the earth. Since
there is more effect of solar radiation in these regions, the temperature is
high. Gas molecules split in ions in this layer. So this layer is known as ion
layer.
Exosphere: It is the
outermost layer of the atmosphere located above 720 km from the surface of the
earth. It is also called fringe region. There is no effect of gravity in this
layer.
Ozone layer
Ozone layer is found
in stratosphere. It is extended from 16 km to 50 km above the earth surface.
Its thickness is 34 Km. This layer is clear and cloudless and jet planes fly in
this layer. This thick layer of air absorbs most of the solar radiation. Due to
absorption of solar radiations, the temperature of the stratosphere increases
as the increase in altitude. Ozone layer protects earth from harmful radiation
and if there is ozone layer depletion then rays of sun enter earth without any
obstacle which causes the rise in temperature of earth.
Ozone layer depletion
The main cause of
ozone layer depletion is the chemical substance produced by the human.
Chlorofluorocarbon is the major chemical substance which destroys the ozone
layer. Along with this, chlorinated compounds such as methyl chloroform, carbon
tetrachloride, methyl bromide etc. also destroy the ozone layer.
The three points
to conserve ozone layer are:
a. The production and
use of CFC should be banned.
b. The alternatives
for the CFCs should be developed.
c. Release of oxides
of nitrogen should be avoided.
Greenhouse effect:
Greenhouse is made up
of glass and plastics which allows the light to pass through it but does not
allow the light to escape. Greenhouse effect is the phenomenon of increasing
the temperature of the earth's surface as in the artificial greenhouse. It is required
to maintain the temperature of the earth's surface. The over greenhouse effect
made lead to increase in temperature, global warming, affect in the environment
and so on. Green house is the process of tapping the radiation of the sun and
making the atmosphere warm. It causes global warming as it increases the
temperature of the earth.
The effects caused by the greenhouse are
as follows:
It absorbs the solar
as well as the earth's existing heat which increases the surface temperature of
the earth.
Increase in the
temperature forces the ecosystem to change which affect in the biodiversity.
As a result of the
greenhouse effect, it increases the temperature and affects the water cycle.
The greenhouse effect
increases the temperature which results in the melt down of polar ice caps
along with global warming.
The importance of artificial greenhouse are
as follows:
a.
Different crop plants can be grown in off seasons.
b.
Summer plants can grow in winter seasons
Industrial gases: In the process
of industrial production, different types of toxic gases, lead, metal, complex
organic compounds etc. are released. These gases produced in the industrial
production are known as industrial gases. Due to the increase in industrial
gases, the air gets polluted. Along with that, it also affects the weather.
When rain falls on the earth' surface, due to the presence of industrial gases,
acid rain occurs.
Click the link below to learn more
1.
https://youtu.be/KXf39bQH6iE
2.
https://youtu.be/ZmOo1B_DI_g
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the link below to test yourself
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