What Are the Layers of the Atmosphere?

Atmosphere Layers

There are 4 primary layers of the atmosphere on Earth. From low to high altitude, they are as follows:

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere

And the thermosphere can be further broken up into the ionosphere and exosphere.

We know all of our weather occurs in the atmosphere. But in which atmosphere layers?

Let’s dig a bit deeper into the purpose of each atmosphere layer and how does it relate to Earth.

1. Troposphere

Atmosphere Layers Troposphere

The troposphere is the layer that we live in. The troposphere starts at ground level and extends about 12 km upwards.

This is where all weather occurs and it’s the air that we breathe.

A significant amount of the troposphere is just 2 gases. For example, 78% is nitrogen and 21% is oxygen. For the remaining 1%, it’s mostly argon and carbon dioxide.

Whether it’s from agriculture, vehicles, electricity or natural disasters, these major sources of air pollution emit from the ground into primarily the troposphere and stratosphere.

2. Stratosphere

Atmosphere Layers Stratosphere

From about 12 km to 50 km upwards is the stratosphere. In this layer, the jet stream blows strong winds eastward.

Airplanes use this layer of the atmosphere when they travel from west to east. It gives an extra push on its tail which helps it move faster.

It also has the ozone layer, which absorbs harmful radiation from the sun. This includes UV rays. But in the south pole, there is a hole and if it enlarges could cause issues.

3. Mesosphere

Atmosphere Layers Mesosphere

The mesosphere is the coldest region of Earth’s atmosphere. It’s somewhere close to -100 degrees Celsius.

In the mesosphere, scientists send unmanned balloons to measure the temperature.

Actually, this layer also protects the Earth from large meteoroids. The friction within this layer causes meteors to burn up.

4. Thermosphere

Atmosphere Layers Thermosphere

The thickest layer in the atmosphere is the thermosphere starting at about 80 km going upwards.

This is where the UV radiation from the sun turns to heat causing the air to be very hot. It can reach temperatures up to 1500 degrees Celsius or more.

Actually, the thermosphere has 2 layers of its own called the ionosphere and the exosphere.

The ionosphere is where the sun’s radiation causes particles to be electrically charged, hence the term ‘ion’. Actually, this is where the sun flows with spectacular light shows for the Aurora Borealis or Northern Lights.

Finally, the upper part of the thermosphere is the exosphere starting at about 550 km. It’s a very thin part of the atmosphere where satellites can freely orbit the Earth.

Reach for the sky

See our meteorology section

Meteorology

5 thoughts on “What Are the Layers of the Atmosphere?”

  1. As a former U.S. Navy Radioman, I learned that R.F. energy has a much greater range during daylight hours utilizing higher frequencies up to and sometimes above 20 megahertz. At night, it was necessary to find an open, clear frequency in the 2 to 6 megahertz range. It required more power to effectively communicate at night. Was this condition perhaps caused by the magnetic density surrounding the earth during these times?

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