Earth Sciences


The ionosphere is an atmospheric layer located at an altitude of about 50 kilometers and 500 kilometers. It has an extremely low density and is traversed by strong radiation as ultraviolet light, which in turn is highly ionized. This ionization causes the electronic bonds of the atoms to break down producing ions of different charges. These ions are responsible for naming this layer, in which it can move freely to be lighter than the others. It is located in the middle of the mesosphere and the exosphere. It is also known as the Thermosphere, a name it receives due to the high temperatures it can generate. These temperatures can even reach 1,500 °C.

What is the ionosphere?

The ionosphere is a layer of the atmosphere between the mesosphere and the exosphere that has a very low density and is traversed by radiation as ultraviolet light, causing the atoms' electronic bonds to allow them to move freely.

Ionosphere’s characteristics

Ionosphere’s composition

The ionosphere is composed of two main layers: the lower layer, which has been designated as layer E and is sometimes also known as Heaviside or Kennelly-Heaviside layer and is located between 80 and 112 km above the Earth’s surface reflecting low-frequency radio waves; and the upper layer, also known as F or Appleton layer, which reflects higher frequency radio waves. The upper layer in turn is further divided into an F1 layer, which begins about 180 km above the ground; and the F2 layer, which emerges about 300 km from the surface. It is composed of free electrons and positively charged ions, which makes it have a tenuous gas and a plasma.


Among the main properties that we can find in the ionosphere, we observe that this layer helps mainly in radio waves reflection that are emitted from earth’s surface, which allows the waves to travel great distances on earth thanks to the ions located in this layer. It disintegrates most meteoroids, at a height between 80 and 110 km, due to friction with the air thus causing meteors or shooting stars. In addition, in the polar regions the particles that the solar wind carries are trapped in the ionosphere giving rise to the famous auroras borealis.

Ionosphere’s function

It allows the transmission of radio waves and prevent meteoroids from impacting the earth are its main functions.

Ionospheric’s layers

According to the density of ionization, the atmosphere has different layers that arise from 90 km. The layers that make up the ionosphere are as follows:


The temperatures that exist in the ionosphere are extremely high, they can even reach 1,500 degrees Celsius, a temperature in which it would be impossible to live.


The ionosphere is very important for humans because it is where we find both the production and the reflection of radio waves that are emitted from the earth’s surface, which enables these radio waves to travel great distances by means of the particles of electrically charged ions present in this layer. It is also important because it is in this layer where meteoroids are disintegrated and where shooting stars are formed.

Written by Gabriela Briceño V.

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