In this article, we are going to talk about atmosphere definition. This particular scientific term is originated from Greek words. In Greek, atmosphere meaning is roughly translated as sphere of vapor. Therefore, atmosphere is roughly translated as the sphere of vapor. The main function of atmosphere is to protect the life on Earth. It consists of several layers that we are going to talk later. Before we dive into layers of the atmosphere, it is important to note that the position of those layers is not shifting. It happens because of gravitational force pulling every layer to Earth.
Atmosphere Definition and Its Layers
Even though the definition of atmosphere above mentioned that it is a vapor sphere, atmosphere is not completely made out of vapor. Other than vapor, some types of gases also present in the atmosphere. Atmosphere is separated into five layers. The border between two atmosphere layers is not clear. It can be higher or lower than it should. That being said, atmosphere layer is governed by gravitational force. Thanks to this force, the layers of the atmosphere are never moving from its original position.
The lower layer of atmosphere is called as troposphere. Troposphere is located from the Earth surface up to 20 km above the surface. In the atmosphere definition above, we learn that atmosphere is not completely made out of vapor. Some essential gases can be found in troposphere. In fact, the function of troposphere is to support the life on Earth. Therefore, oxygen and nitrogen can be found in this layer.
Based on the definition of atmosphere, the next layer is stratosphere. Stratosphere is separated from troposphere by thin layer called as tropopause. Stratosphere begins right after troposphere ends. It goes until 50 km above Earth surface. There is nothing much can be said about this atmosphere layer. The only thing can be found in this layer is the weather balloon. Unlike other aircraft, the air resistance in this layer is thin. Therefore, it is good for monitoring the weather through weather balloon technology.
The next layers of the atmosphere are the mesosphere and ionosphere. Those layers often referred as single layer. As the name suggests, it is located right in the middle of the atmosphere. That being said, it starts from 50 km up to 85 km above the Earth surface. In the explanation about atmosphere meaning above, we know that atmosphere protects life on Earth. Mesosphere protects life on Earth from meteors. Sometimes, meteor passing by Earth orbit is pulled down by gravitational force of earth. When penetrating the mesosphere layer, it begins to burn. It happens since mesosphere has great density. Any celestial body penetrating the atmosphere will be burned until it has nothing left. Another function of mesosphere is to reflect radio wave. It helps human living on earth to communicate with each other.
Read too: Understanding the Biosphere Definition.
Looking back at the definition of atmosphere, the atmosphere is continued with thermosphere layer. It gets its name from the high temperature of the gases in it. The location of thermosphere begins roughly from 85 km above Earth surface up to 690 km. As you can see in this explanation of atmosphere meaning, thermosphere is the thickest layer among the others. A unique natural phenomenon that happens on thermosphere is called as aurora. Even though the atmosphere definition above mention about the function of atmosphere layer, thermosphere has no specific function other than as a place for shuttle to go.
Above 690 km away, we have exosphere. There is no limit on where this layer ends. One thing for sure is that the air density on this layer is extremely low. Therefore, it is not good for sustaining life. After understanding atmosphere definition, you can see that every one of them has their specific function.