Composition of atmosphere

Introduction:

We all know that the presence of life on Earth makes it a unique planet. One of the basic prerequisites for life on this planet is the presence of air that surrounds the earth and is known as the atmosphere. The air is a mixture of several gases that surrounds the earth. Different gases, water vapour, and dust particles make up the atmosphere’s composition and structure. The atmosphere is dynamic, changing with time and location. The atmosphere comprises layers of gas and solid particles that float above the ground. It stretches for miles from the earth’s surface. The gravitational pull of the earth keeps them around it. They do, however, thin down as you get further away from the earth’s surface.

Atmosphere:

The atmosphere is a composition of gases, dust particles and water vapours that protects the planet. The atmosphere on Earth contributes to human survival. Apart from giving us air to breathe, it protects us from the harmful solar ultraviolet (UV) radiation, provides heat to the surface of Earth and mainly prevents unwanted temperature changes between day and night. The atmospheres of the other planets in our solar system also exist, but none of them has the same ratio of gases or layered composition and structure of the atmosphere as Earth has.

Structure of Atmosphere

The Earth’s atmosphere is divided into various areas or levels. Temperatures, pressures, and phenomena are unique to each layer. We live in the troposphere, the lowest layer of the atmosphere, where most clouds form and nearly all weather related changes occur here. The stratosphere contains the jet streams and the ozone layer, where some jet aircraft fly. Because there are essentially no air molecules to absorb heat energy, temperatures in the mesosphere are at their lowest. The thermosphere is the broadest layer of the atmosphere which absorbs much of the damaging radiation that reaches Earth from the Sun, is the layer farthest from the surface. The exosphere represents the passage from Earth’s atmosphere to space.

It is also of great importance to know what the composition of the atmosphere is and know the answer to the question if the composition of the atmosphere is changing? 

What is the composition of the atmosphere?

Broadly the composition of the atmosphere is stated as follows:

Gases: 

• The atmosphere is made up of a variety of gases.  Nitrogen and Oxygen are the two primary gases in the atmosphere, which make up 78% and 21% of the atmosphere. The other gases in the atmosphere include carbon dioxide, hydrogen, helium, argon and more, forming the rest of 1%.
• The proportion of gases fluctuates in the upper layers of the atmosphere to the point where oxygen is almost non-existent.

Water vapour:

• Water vapour is a gaseous form of water found in the atmosphere. Its greatest level in the atmosphere, which is found in warm and moist places, might be up to 4%.
• It works as a blanket, keeping the ground from becoming too cold or too hot. Water vapour also has a role in the air’s stability and instability.

Dust particles:

• Dust particles are most commonly found in the atmosphere’s lower levels. Sand, smoke-soot, sea salt, ash, pollen, and other particles contain dust particles.
• The condensation of water vapour is aided by these dust particles. Water vapour condenses in the form of droplets around these dust particles during condensation, resulting in clouds.

Is the composition of the atmosphere changing?

The chemical makeup of the earth’s atmosphere is known as atmospheric composition. Many different gases make up our atmosphere. Nitrogen, oxygen, and argon are the most prevalent gases. However, the precise amount of each gas is always changing.

Humans have changed the composition of the atmosphere and considerably increased the number of greenhouse gases in the atmosphere since the industrial revolution. These gases cause the atmosphere to trap more heat, similar to a greenhouse, resulting in long-term climatic changes. Carbon dioxide is the most well-known greenhouse gas.

Scientific investigations have revealed significant changes in the chemical makeup of the lower atmosphere, as well as significant changes in the higher atmosphere. Both of these discoveries have far-reaching ramifications for terrestrial life and human society.

Conclusion:

The atmosphere is an essential component of our planet. It is related to the earth through the earth’s gravitational force. It aids in preventing damaging ultraviolet radiation and the maintenance of the proper temperature required for life. The composition and structure of the atmosphere include five layers of the atmosphere, and also comprises various gases, water vapours and dust particles. All life forms require a specified temperature range and a specific range of solar radiation frequencies to carry out their biophysical processes. In other words, the atmosphere controls the amount of solar energy that enters the earth’s atmosphere and provides the best atmosphere to live in.