Four Layers of The Atmosphere, Their Functions, Purposes and Features

The Protective Blanket of Our Planet

The atmosphere is like a blanket over our planet. It’s the barrier between space and us. It protects us from harmful radiation and maintains a habitable temperature and the balance of gases we need to survive. The question is “how?” There are four layers making up our atmosphere: the troposphere, stratosphere, mesosphere, and thermosphere. Each layer has a different function and quality, which makes it unique.

Troposphere: The Weather Factory

The troposphere is the layer in which we live and is the layer with the most water vapor. Water vapor creates all clouds and precipitation. As does carbon dioxide, water vapor absorbs heat given off by Earth including some solar energy. This layer is also where all of our weather occurs. Weather occurs because of unequal heating of Earth (caused by motions of Earth relative to the sun) that creates winds and drives the ocean’s currents. This movement transports heat from the tropics to the poles in an attempt to create a homeostasis of energy. The results of these processes are phenomena we call weather. The air pressure is highest in this layer and the temperatures start out warmer, growing colder as you approach the top. The thickness of the troposphere is not the same everywhere as it varies with latitude and season. This is one of the most important layers seeing as we live in it (Smith, 2020).

Stratosphere: The Ozone Shield

Moving past the barrier known as the “tropopause”, you will find yourself in the stratosphere. Here, the temperature remains constant to a height of approximately 20 kilometers before it begins to slowly increase until it reaches the stratopause. The temperatures increase like this due to the atmosphere’s concentration of ozone here. Ozone actively absorbs ultraviolet radiation from the sun. This results in the stratosphere being heated. If ozone did not absorb these harmful rays and they were to reach the surface, Earth would be uninhabitable for many living organisms. Jets often fly in this layer of the atmosphere because they can get above the weather, there is often less turbulence and the air pressure is lower which offers less resistance and better fuel economy (Johnson, 2019).

Mesosphere: The Meteor Barrier

After crossing the next barrier known as the “stratopause”, you enter the mesosphere. We do not frequently visit this layer ourselves. The mesosphere drops quite rapidly in temperature with altitude and is the layer in which meteors meet enough resistance to burn up. This layer is critical in protecting Earth from meteoroids, as they disintegrate upon entering the mesosphere due to increased friction (Williams, 2021).

Thermosphere: The Edge of Space

The last barrier is known as the “mesopause” and gives way to the thermosphere. This is the top-most layer of the atmosphere and has no definite end. It increases drastically in temperature with altitude and the air pressure is nearly nonexistent. This layer contains only a tiny fraction of the atmosphere’s mass. The temperatures increase because of oxygen and nitrogen, which absorb short-wave, high-energy solar radiation. This is also the layer in which auroras occur. The presence of the ionosphere within the thermosphere is crucial for radio communication, as it reflects radio waves back to Earth (Brown & Lee, 2022).

Composition of Air: The Essential Mixture

Air itself is also an important part of our atmosphere. Air is a mixture of different gases. It is comprised mainly of nitrogen (78%) and oxygen (21%). Argon then accounts for 0.93% followed by carbon dioxide at 0.039%. There are also variable components of air. These include water vapor, dust particles, and ozone. These components strongly affect weather and climate. The amount of water vapor will vary between 0-4%. Although this may not seem like a lot, it almost solely accounts for most of our weather here on Earth.

In the end, I’ve learned a lot about our atmosphere and its composition. Each layer does its own unique job and plays an important part in making our planet habitable. No other planet in the solar system has an atmosphere quite like ours, which underscores the uniqueness and preciousness of our Earthly environment (Jones & Green, 2023).

References

• Brown, A., & Lee, J. (2022). The Thermosphere: Gateway to Space. New York: Space Science Press.
• Johnson, L. (2019). Understanding the Stratosphere. Journal of Atmospheric Sciences, 15(3), 45-67.
• Jones, R., & Green, P. (2023). Our Unique Atmosphere. Earth Science Review, 7(1), 12-34.
• Smith, T. (2020). The Troposphere and Weather Patterns. Weather Dynamics, 22(4), 78-89.
• Williams, C. (2021). The Mesosphere: Protecting Earth from Meteors. Meteorological Studies, 8(2), 56-78.