The ionosphere is a layer of the atmosphere located about 50 kilometers and 500 kilometers high. It has an extremely low density and is crossed by strong radiation in the form of ultraviolet light, which is itself highly ionized . This ionization causes the electronic bonds of the atoms to break, producing ions of different charges. These ions are responsible for giving name to this layer, in which they can move freely as it is 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 for the high temperatures that it can generate, these temperatures can even reach 1,500 ° C.


What is the ionosphere?

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

  • Characteristics of the ionosphere
  • Composition of the ionosphere
  • Properties
  • Function of the ionosphere
  • Layers of the ionosphere
  • Temperature
  • Importance

Characteristics of the ionosphere

  • It is a dynamic system that is in change
  • It has great variations in weather conditions .
  • Responsible for allowing electromagnetic emissions .
  • It is a monitor of climatic changes .

Composition of the ionosphere

The ionosphere is made up of two main layers: the lower layer, which has been designated as the E layer and is sometimes also known as the 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 the F or Appleton layer , which reflects radio waves with higher frequencies. The upper layer in turn is further divided into an F1 layer, which begins about 180 km above the earth; and the F2 layer, which arises about 300 km from the surface. It is composed of free electrons and positively charged ions which makes it have a faint gas and a plasma .



Among the main properties that we can find in the ionosphere, we observe that this layer helps mainly in the reflection of radio waves that are emitted from the earth’s surface, which allows the waves to travel great distances on the earth thanks to the ions that are located in this layer. In it, most meteoroids disintegrate , 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 northern lights .

Function of the ionosphere

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

Layers of the ionosphere

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

  • Layer D : This layer is located 60 kilometers away and only appears during the day. It is very absorbent for frequencies below about 10 MHz, thus protecting the Earth’s surface from much of the space radiation . This is the layer in which occurs attenuation of radio waves through absorption.
  • Layer E or Kennelly-Heaviside layer (or Heaviside layer): It is located at 80-110 km. It is a layer of ionized gas that reflects medium frequency radio waves and can vary depending on the season of the year. It is a fairly regular layer and its ionization density depends on the angle of radiation caused by the sun. Sometimes a layer can form on top of the E layer and is known as a sporadic layer , formed by ionized clouds that appear and disappear over the hours.
  • F layers or Appleton layers . This layer is located between 180-600 km. The F layers suffer an elevation during the night so their reflection properties change and it is responsible for reflecting electromagnetic waves that are around 300 or 500 km above sea level.
  • Layer F1 . Located approximately 180-300 km. It constantly mixes with the E layer due to the fluctuation suffered by both. Its density will also depend on solar radiation, reaching its maximum points at noon. Here occurs absorption of radio waves .
  • Layer F2 . It is the highest layer of the ionosphere and is located between 300-600 km away. It begins when dawn happens and reaches its maximum ionization point between two and three hours after noon .


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 of utmost importance for humans because in it we find the production and reflection of radio waves that are emitted from the earth’s surface, which enables these radio waves to travel great distances by means of charged ion particles. electricity present in this layer. Also, it is important because it is in it where meteoroids are disintegrated and where shooting stars are formed .

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