Ozone Layer: Definition, Importance, Diagrams, Depletion

Have you ever wondered if there is any invisible screen that protects us from ultraviolet rays? Yes, the answer is the ozone layer. This layer has the capacity to absorb around 97-99% of the harmful ultraviolet radiations coming from the Sun that can harm life on Earth. The ozone layer, which makes up to 0.00006% of Earth’s atmosphere, is getting thinner and thinner because of man-made chemicals like chlorofluorocarbons(CFCs).

Many deaths are reported due to skin cancer, skin diseases and weakened immune systems due to the thinning of the ozone layer. In this article, we will provide detailed information about the ozone layer. Scroll down to learn more!

What is an Ozone Layer?

The Ozone Layer was first observed by the French physicists Charles Fabry and Henri Buisson in 1913. International Day for the conservation of the Ozone Layer is celebrated on September 16 every year. The ozone layer is the protecting blanket that absorbs most of the ultraviolet radiation reaching the Earth from the Sun. The ozone layer in the atmosphere is thicker over the poles than on top of the equator. The ozone layer assumed to be relatively stable over the past several hundred million years is now in a state of continuous damage. The ozone measurement instruments and techniques are varied. The Dobson spectrophotometer and the filter ozonometer called M83 are commonly utilized to measure atmospheric ozone.

Ozone Layer in the Atmosphere

The Earth’s atmosphere is composed of 5 layers namely, troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
One major highlight of the stratosphere is that it contains the ozone layer. The ozone layer is primarily present in the lower stratosphere. Furthermore, the thickness of the ozone layer may differ depending upon the seasonal and geographical changes. There is the highest concentration of ozone between 20-30 km. This region is thus called Ozonosphere.

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Fig: Ozone Layer in Earth’s Atmosphere

Formation of Ozone

The formation of ozone takes place as follows:

1. When the Sun’s rays split oxygen molecules into single atoms, ozone is created in the atmosphere.
2. Ozone is made up of 3 atoms of oxygen.
3. When an oxygen molecule is broken into two atoms by ultraviolet radiation, the unstable atoms combine with two other oxygen molecules forming triatomic ozone (O₃) gas.

4. The ozone thus formed is unstable in nature and can decompose to form molecular oxygen. So, it can be said that a dynamic equilibrium is there between the formation and decomposition of the same.

Importance of Ozone Layer

The ozone layer absorbs the harmful ultraviolet radiation from the Sun. In the absence of the ozone layer found in the atmosphere and in the event of ultraviolet rays reaching Earth’s surface, our planet would have been unfit for human habitation and other living beings. Thus the ozone layer safeguards us from these harmful rays and proves to be a boon to human beings.

Fig: Importance of Ozone Layer

Ozone Depletion and Causes

Ozone layer depletion is the step by step thinning of the Earth’s ozone layer in the upper atmosphere caused due to the release of chemical compounds containing gaseous bromine or chlorine from industries or other human activities.

Causes of Ozone Depletion
The causes of ozone depletion are as follows:
1. Chlorofluorocarbons or CFCs are the main cause of ozone layer depletion. These are released by spray aerosols, solvents, refrigerators, air-conditioners, etc.
2. The molecules of chlorofluorocarbons in the stratosphere are broken down by ultraviolet radiation and release chlorine atoms. These atoms react with ozone and destroy it.
3. The nitrogenous compounds such as \({\rm{N}}{{\rm{O}}_{\rm{2}}}{\rm{,\; NO,\; }}{{\rm{N}}_{\rm{2}}}{\rm{O}}\) are highly responsible for the depletion of the ozone layer.

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Fig: Ozone Depletion

How can the Ozone Layer be Protected?

In June 1990, representatives of 53 nations agreed to ban major production and use of ozone-destroying chemicals by the year 2000. The Montreal Protocol is a global treaty with the aim of protecting the Earth’s ozone layer by decreasing the amount of chemicals that deplete it. This phase-out plan involves both the production and consumption of ozone-depleting substances. To save the ozone layer, timely action is the only solution. Illegal trade is a major barrier, as substantial demand for these harmful chemicals still exists. Each country has to take strict steps to ban the use of such chemicals. Another step that can help is to create worldwide awareness against the use of CFCs to prevent further depletion of the life-saving ozone layer.

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Summary

The ozone layer is the protecting blanket that absorbs most of the ultraviolet radiation reaching the Earth from the Sun. The ozone layer in the atmosphere is thicker over the poles than on top of the equator. Ozone depletion can cause a variety of health problems in humans, including skin cancers, eye cataracts and a reduction in the ability to fight off disease. The ozone layer is the portion of the Earth’s atmosphere that carries moderately high concentrations of ozone gas, which is an inorganic molecule with the chemical formula O₃. One of the measures to save the ozone layer is timely action.

FAQs on Ozone Layer

Q.1. What is the ozone layer?
Ans: The ozone layer is the protecting blanket that absorbs most of the ultraviolet radiation reaching the Earth from the Sun. The ozone layer in the atmosphere is thicker over the poles than on top of the equator.

Q.2. What destroys the ozone layer?
Ans: Chlorofluorocarbons, unregulated rocket launches, nitrogenous compounds, natural causes such as volcanic eruptions, sun-spots, etc., are the main causes that destroy the ozone layer.

Q.3. Why is there no ozone layer in Australia?
Ans: Australia ozone layer is extremely thinned due to heavy use of ozone-depleting substances such as chlorofluorocarbons and hydro-chlorofluorocarbons.

Q.4. Where is the ozone hole located?
Ans: The formation of ozone holes occurred in two places: the Arctic and Antarctic regions. Scientists have discovered a major hole in the ozone layer over the Antarctic.

Q.5. What does ozone smell like?
Ans: Ozone is a pale blue gas with a sharp pungent smell that is similar to that of chlorine.

We hope this detailed article on the Ozone Layer helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.