Climate change and Atmosphere | SEE notes

Atmosphere:

Definition: The atmosphere is a layer of gases and dust particles around our earth.
The earth has acceleration due to gravity. The atmosphere contains 78% of N₂, 21% of O₂, 0.3% of Co₂ by its volume. Atmosphere extends above 1600 Km from the earth.
Diagram:

The layer or division of atmosphere:

a) Troposphere.
b) Stratosphere
c) Mesosphere.
d) Thermosphere.
e) Exosphere, etc.

a) Troposphere:

Definition: The first layer of the atmosphere which is extended up to 60 km height from the earth’s surface is called Troposphere.
Features:
a) It is a layer where weather formation takes place.
b) It is a layer where the cloud is formed, and lighting takes places.
c) The temperature decreases by 6.5°C per kilometer height, etc.

b) Stratosphere:

Definition: The second layer of the atmosphere which is extended from 16 to 50 km above the troposphere is known as Stratosphere.
Features:
a) Its outermost boundary layer is called stratopause.
b) The stratosphere is also called the ozone layer.

c) Mesosphere:

Definition: The layer of atmosphere above the stratosphere extending from 50 km to 80 km is called Mesosphere.
Features:
a) In this layer, temperature is decreased by height.
b) Meteors burn out, etc.

d) Thermosphere:

Definition: The layer above the mesosphere extending from 80 km to 720 km is called Thermosphere.
Features: 
a) In this layer density of the gas(air) is low.
b) Its upper surface has H₂ and He and lower surface have N₂ and O₂ in a small amount, etc.

e) Exosphere:

Definition: The outermost layer above 720 km is called Exosphere.
Features:
a) It is also called Fringe layer.
b) The temperature of this layer varies from 1200°C to 6000°C.

• History of Earth
• Electricity and Magnetism
• Force

Ozone layer/ Ozonosphere:

Definition: The ozone is a gas with three oxygen atoms is known as the Ozone layer.
Features:
a) Its molecular formula is O₃.
b) This layer present in Stratosphere.
c) It is a protective layer because it absorbs 99% harmful UV radiation, etc.
Ozone layer formation:
O₂ ——-UV  radiation——-> O+O
O₂ ——-UV  radiation——-> O₃(Ozone)

Importance of the ozone layer:
a) It absorbs 99% harmful UV radiation.
b) It establishes a balance between temperature and weather.
c) It protects the chlorophyll of plant from burning.
d) It protects us from skin cancer, blindness, etc.
e) It safes aquatic animals, etc.

Depletion of Ozone layer: The ozone layer depletion is a process in which the ozone layer becomes thin and UV radiation easily penetrates and come to earth.

Causes of Ozone layer depleting: The main causes of ozone layer depleting is CFCs (Chlorofluorocarbons) emitted from foam, aerosols, refrigerator, air conditioner, fire extinguisher, etc.

Process:
CF₂ Cl₂ —— UV rays ——> CF₂Cl+Cl (Nascent/atomic chlorine)
O₃+cl —— UV rays —–> ClO+O₂
O₃+O —— UV rays —–> O₂+O₂

∴ The nascent chlorine or atomic chlorine is responsible for ozone layer depletion.

Effect of Ozone layer depleting: 
a) Human beings: Cancer, Blindness, loss of immunity power.
b) Aves: It decreases egg laying capacity and the egg becomes thin shelled.
c) Aquatic animals: Mostly destroyed.
d) Vegetation: The chlorophyll is destroyed and most of the plants are lost, etc.

Conservation of Ozone layer: 
a) Reduce the use of CFCs.
b) Reduce the use of chemical fertilizer.
c) We should replace fossil fuel by using the alternating source of energy.
d) We should promote public vehicles rather than private vehicles, etc.

Greenhouse:

Definition:  The artificial house which is design for cultivating long day plants in short day region of the world is called Greenhouse.
Diagram:

Greenhouse gases: The gases like carbon dioxide, Nitrous Oxide, Methane, Sulphur dioxide, chlorofluorocarbons prevent the return of ultraviolet radiation from the earth and cause the increment of a temperature of the earth. So, those gases are called Greenhouse gases.
a) Co₂
b) N₂(Nitrous oxide)
c) CH₄ (Methane)
d) So₂ (Sulfur dioxide)
e) Ozone (O₂)
f) Water vapor (H₂o), etc.

A disadvantage of the Greenhouse:
a) Global warming,
b) Weather pattern, etc.

Greenhouse effect:
The gases like carbon dioxide, Nitrous Oxide, Methane, Sulphur dioxide, chlorofluorocarbons let the entrance of the ultraviolet radiation but stop them exist. As a result, the ultraviolet radiation changes into heat which causes an increment of a temperature of the earth is called the greenhouse effect.

Acid:

Definition: Falling of acid along with water during rainfall is called acid rain.

A process of acid formation:

a) H₂So₄ Formation:
So₂ + O₂ ——–> So₃ (Sulphuric oxide)
So₃ ——-> h₂so₄

b) HNO_{3 Formation:}
No (Nitric oxide) + O₂ ——-> No₂ (Nitrogen dioxide)
NO₂ + O₂ ——-> N₂O₅ (Nitrogen pentaoxide)
N₂O₅ ———> HNO₃

c) H₂Co₃ Formation:
Co₂ + H₂o ——-> H₂Co₃₀

Gases:

Industrial gases: The thick layer of gases produced by industries are called industrial gas.
Example: So₂, Nitrogen oxide, etc.

Industrial smog: Industrial smog is the cloud of smoke gases solid and liquid particles released by industries.

Climate change: The change in the change in the statistical distribution of weather patterns when that change lasts for extended periods is called climate change.

Agenda-21: The work plan think globally and act locally was brought in practice to address the issues of climate change and sustainable development in the 21st century is called Agenda-21.

Kyoto Protocol: The Kyoto protocol is the international carbon emission reduction agreement.

Efforts made on the international level:

• United Nations Convention about climate change.
• Conference of the Concerned and the Recognized Countries about climate change.
• Agenda-21.
• Kyoto protocol.
• Intergovernmental forum.
• Methods of minimizing the emission of greenhouse gases according to the Kyoto Protocol.
• Minimizing the carbon emission resulted due to deforestation, etc.

Give the reasons:

a) The greenhouse effect is advantageous as well as disadvantage.
Ans: Greenhouse absorbs heat then its warm in winter in summer it makes 2X heat. Hence, The greenhouse effect is advantageous as well as disadvantage.

b) Temperature increases remarkably in the stratosphere.
Ans: Temperature increases remarkably in the stratosphere because of temperature gradually increase in height.

c) Ozone layer must be conserved.
Ans: Ozone layer must be conserved because it prevents UV rays.

d) It is better not to use a refrigerator with CFC.
Ans: It is better not to use a refrigerator with CFC because greenhouse’s covered layer reflect inside ray but outside not share rays.

e) The thermosphere is also known as the ionosphere.
Ans: The thermosphere has the direct effect of solar radiation, so gases are ionized. Hence, The thermosphere is also known as the ionosphere.

f) The exosphere is also known as the fringe region.
Ans: Exosphere varies from 1200°C to 6000°C. Hence, The exosphere is also known as the fringe region.

g) Stratosphere is also known as Ozonosphere.
Ans: Ozone layer absorbs UV radiation and protects us from the hazardous effect of UV. Hence, Stratosphere is also known as Ozonosphere.

Name the layer of the atmosphere where:

1. Cloud and fog formation occur.
   Ans: Stratosphere.
2. Streaks of hot gases released from meteors are seen.
   Ans: Mesosphere layer.
3. Gases ionize to form positive ions and electrons.
   Ans: Thermosphere.
4. Sun’s ultraviolet radiation are absorbs.
   Ozone layer.
5. Frequent storm ozone.
   Ans: Mesosphere.
6. Temperature range between -109°C to 1500°C.
   Ans: Mesosphere.