The thermosphere is a layer of the earth’s atmosphere that can also be known by the name of ionosphere , it is the layer that is located between the mesosphere and the exosphere , and which has an extension that begins approximately between 80 and 120 kilometers from the Earth, managing to extend between 500 and 1000 kilometers from the earth’s surface. It is in this layer where ultraviolet radiation , and especially the gamma rays and X-rays that originate from the sun, cause a constant ionization of sodium atoms and of various types of molecules. While this process ofionization the gases that make up the thermosphere raise their temperature several hundred degrees, and this process is where it derives its name. This is the layer of the atmosphere in which we can observe space shuttles . The air particles within this layer are widely separated. It is the fourth layer of the atmosphere and its name is due to the high temperatures caused by already ionized gases, and from there it derives its second name.


What is the thermosphere?

The thermosphere is the fourth layer of the Earth’s atmosphere and its name is due to the high temperatures it reaches due to the ionization of the gases that make it up, in addition to the ionization of sodium atoms and various molecules that are found in it, this caused by ultraviolet radiation.

  • Thermosphere characteristics
  • Composition of the thermosphere
  • Thermosphere function
  • Temperature
  • Importance
  • Northern Lights

Thermosphere characteristics

Among its main characteristics of the thermosphere we can mention the following:

  • In this layer, the ionization of the molecules occurs due to ultraviolet radiation, gamma rays and X-rays from the sun.
  • In it, meteorites disintegrate as they brush its air.
  • At the poles , the particles that are carried by the solar wind are trapped in the earth’s magnetic field , giving rise to the northern lights .
  • It is located above the mesosphere and is the fourth layer that the earth has.
  • Its temperature changes with solar activity.
  • In its internal part we can find a sub-layer called the ionosphere in which radio waves are reflected.
  • The boundary between the thermosphere and the exosphere above it is called a thermopause . At the bottom we can find the mesopause , which is the boundary between the thermosphere and the mesosphere .

Composition of the thermosphere

The air in the lower atmosphere is mainly made up of a mixture of about 80% nitrogen (N2) molecules and about 20% oxygen (O2) molecules . In and above the thermosphere, gas particles collide in such a way that the gases separate in some way based on the types of chemical elements they contain. The photon energy ultraviolet and X – rays from the sun are also responsible for breaking molecules in the thermosphere. In the upper thermosphere, atomic oxygen (O), atomic nitrogen (N), and helium (He) are the main components of air.

Thermosphere function

The thermosphere is very important for human life as it helps enormously to protect the earth, in addition, it enables space exploration and modern forms of communication. It recycles water, absorbs energy from the sun and creates a moderate temperature . This helps protect the earth from the extremely cold temperatures that come from space. It also absorbs a large part of the ultraviolet and X-ray radiation caused by the sun.


It is important to mention that the temperature in the thermosphere increases considerably as it rises in distance and it does so very quickly. In the upper part the temperature does not change or vary much. This temperature is oscillating depending on whether it is day or night. Also, the temperature will depend on how active the Sun is during the sunspot cycle . In this way we can say that the thermosphere has a warmer temperature when the sun is very active, a phase known as ” solar maximum “, and is less hot during ” solar minimum “.


The sublayer that we find within the thermosphere known as the ionosphere is a layer that contains charged or ionized ions , and these have a very important role in wireless communications and radio broadcasting , since thanks to it the radio waves that can be reflected radio stations and communication centers broadcast. The ionosphere is surrounded by two magnetic belts known as Van-Allen belts . These belts play an important role in the scattering of cosmic radiation , away from the Earth.

Northern Lights

An aurora borealis is also known by the name of polar lights , northern lights (aurora borealis) or southern lights (aurora australis), it is a screen of natural light in the sky of the earth. It is a phenomenon worthy of admiration that emits rays full of light without causing any increase in the atmosphere, and occurs when there is an expulsion of solar mass that collides with the north and south poles of the external part of the atmosphere in which it is produces diffuse light composed of protonic particles responsible for diffusing color. The arrangement of the earth’s magnetic field collides with space producing the lights that we know as aurora borealis .

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