Self Assigned Essays

Self Assigned Essay #1: Atmospheric Layers

Why are the main 5 layers of the atmosphere important?

By: Jay Allen

     There are 5 main atmospheric layers. But why? Are they all necessary? Why are they each important separately? Similarly, why are they important together? This self assigned essay will answer those questions and more for you.

     The 5 main atmospheric layers are, in order from closest to farthest: the Troposphere; the Stratosphere; the Mesosphere; the Thermosphere; and the Exosphere. I will discuss each one separately and then explain how it contributes to the Earth as a whole in 5 different paragraphs, and then make one to show how they all help each other out.

     The Troposphere is the atmospheric layer closest to Earth's surface, only about 7 to 15 kilometers (5 to 10 miles) away. The Troposphere is made up of 78% Nitrogen, 21% Oxygen, and the remaining 1% is argon, with traces of hydrogen ozone and other elements. 75% of the atmosphere's mass is located in the Troposphere. Water vapor is primarily concentrated in this layer. Both the temperature and water vapor content in this layer rapidly decrease with altitude. Water vapor is important because it absorbs solar energy and thermal radiation from Earth's surface, which regulates the air temperature. Uneven heating of the Earth from the sun causes convection currents in the Troposphere. Convection currents are large scale patterns of winds that move heat and moisture around Earth. This creates wind around the globe, which in turn controls areas of high and low air pressure, called turbulence. Smog also forms in the Troposphere, which restricts visibility and can cause irritation in your eyes and throat. The water cycle also occurs in the Troposphere. The water cycle helps form clouds, which in turn help produce rain. The Troposphere is important for giving us weather and helping us live our everyday lives.

     The Stratosphere is the next atmospheric layer. It can be anywhere from 6 to 50 kilometers (4 to 31 miles) above Earth's surface. The Stratosphere contains Ozone gas, a large amount of it, and makes up 20% of the atmosphere's mass. Ozone is formed naturally in the Stratosphere. Ozone is considered a pollutant in the Troposphere, but in the Stratosphere it is essential to life on Earth for absorbing UV radiation that is biologically harmful. It absorbs most of the UV radiation from the sun, making life on Earth possible. The Stratosphere is where jets like to fly, and birds like swans, cranes, and vultures can also fly here. The Stratosphere is important for protecting us from harmful Ultraviolet rays sent from the sun that have evil intentions to kill us but fail.

     The Mesosphere is the third of the five most important atmospheric layers. It extends from 50 to 85 kilometers (31 to 53 miles) above the surface of the Earth. The Mesosphere is made up of oxygen, carbon dioxide, and nitrogen. The Mesosphere contains about 1 ½ of the overall atmospheric mass, and is the coldest of all the layers. The Mesosphere burns up most meteors and asteroids before they are able to reach Earth's surface; it is estimated that approximately 40 tons of meteors fall towards Earth each day, and the Mesosphere burns them all up before they can absolutely murder us like they allegedly did to the dinosaurs. Shooting stars are actually meteors being destroyed in the Mesosphere. The Mesosphere can get anywhere from -220°F to 23°F. It can become cold enough to freeze water vapor in the atmosphere and turn them to ice clouds. These ice clouds are called noctilucent clouds or polar mesophoric clouds. These clouds are more visible at sunset from the Earth's poles. The Mesosphere is important for burning up meteors and asteroids before they can destroy the world as we know it.

     The Thermosphere is next in line, second to farthest from Earth's surface. It's 90 to 1000 kilometers (56 to 621 miles) from Earth's surface. Oxygen, nitrogen, and helium are the main components of air in the upper Thermosphere. Much of the X-ray and UV radiation from the sun is absorbed in the Thermosphere. The more high energy radiation the sun gives off, the bigger the Thermosphere gets, as it expands with the rates the sun gives. Because of that the height of the top of the Thermosphere varies, going anywhere from 500 kilometers to 1000 kilometers. Sometimes it goes even higher than that. The Southern and Northern lights primarily occur in the Thermosphere as well. The Thermosphere is important for keeping harmful UV radiation away.

     Wait. Hold up. Both the Stratosphere and the Thermosphere protect us from UV radiation? That's kinda weird. Why two? Isn't one layer protecting us plenty? I know, I know. You're confused. As am I. I'm doing some research to figure out the answer to these new questions. So. The Stratosphere holds the ozone layer and that protects us from basically all the UV rays. The Thermosphere helps out. The Thermosphere burns up most of the UV rays and X-rays, and then the Ozone layer in the Stratosphere gets what the Thermosphere missed. It's double protection to help us even more. UV rays are really harmful and dangerous, so maybe instead of questioning things we should say thank you to them both. The Stratosphere and Thermosphere literally save our lives and yet you doubt them both. Shame on you. Now that we're done questioning things, let's move on to the last layer: the Exosphere.

     The Exosphere is the furthest and last (but certainly not least) layer in the five main layers of the atmosphere. There's no obvious place where the Exosphere fades into the great unknown wonder that is outer space. Different definitions put the Exosphere between 100,000 and 190,000 kilometers (62,000 and 120,000 miles) above the surface of the great planet Earth. Although the Exosphere is the furthest away, it's also Earth's first line of defense against the big, bad, evil sun, and by that I mean the rays that it produces. It's also the first layer to come into contact with things like asteroids, meteors, and cosmic rays, and is the first layer there that can help us survive and not die because of them. It's the only atmospheric layer to have a definite shape. In simpler terms, the Exosphere is a solid while the Mesosphere, Thermosphere, Troposphere, and Stratosphere are all liquids. Use science to explain science. The Exosphere is important for being our first line of defense against things like meteors, harmful UV rays, and dangerous space dinosaurs. Okay, maybe not so much against the space dinosaurs, but definitely against the other things.

     So. Why do we need all of them? Well, each individual layer does its own thing to protect Earth, whether it seems important or... not so much. They all have a role in protecting Earth from space and helping regulate things until we get to the life we live in today. If one of the layers were missing, I'm sure life on Earth would be very different. Without the Troposphere, there's no rain. No rain, and there goes a lot of our food. Get rid of the Stratosphere and we would have to be even more cautious against the UV rays the sun gives, which means we would have to go outside a lot less. You never know how terrible it feels being stuck inside until you don't have a choice. Take away the Mesosphere and there would be a lot more threats on life. At any moment a meteor or asteroid could come in and kill some of us, most of us, or even all of us. If the Thermosphere wasn't here, there would again be a lot more UV rays, but they'd be so much harsher because they're not being burned up before they can do too much damage. And if the Exosphere was gone, there would be no front defense line. We would just be a planet floating through space without any major means for protection, which basically means we would be absolutely screwed. Every single layer of the atmosphere is important, very much so. They help us survive and thrive so we don't have to live day-by-day in complete fear, because even though we can't really protect ourselves from meteors, we have something to do it for us so we don't need to worry about it. So the next time you go outside, maybe take a second to appreciate the fact that you can. The atmospheric layers have got your back, both when you realize it and when you don't.