Know the layers of the Earth’s atmosphere

The atmosphere around the Earth is not a large layer. It is made up of a few layers, each of which has its own characteristics.


What do you want to know

  • Five layers make up the Earth’s atmosphere
  • The layer that affects us the most is the troposphere
  • Some areas of the atmosphere reach 3,600 degrees
  • The atmosphere protects us and makes the Earth habitable

The atmosphere runs from the troposphere to the exosphere, and each layer has a purpose.

A profile of the atmosphere. (NO)

Troposphere

The first layer and the one that affects us the most is the troposphere. The reason this layer is so important is that almost any weather happens here, from thunderstorms to snowfall to sunny days.

This layer extends from 4 to 12 miles above the Earth’s surface, varying by location. At the equator it extends up to 12 miles, but at the poles it only reaches about 4 miles.

Density also decreases with height, which means the temperature also drops as you go up, from 62 degrees to -60 degrees at the tropopause.

Occasionally, a temperature inversion occurs in a small layer of the troposphere, where temperature increases with altitude. This can lead to haze, fog, or more pollution near the surface.

Stratosphere

The next layer is the stratosphere, which extends from the top of the troposphere to 31 miles above the Earth’s surface.

Here, ozone is formed, which produces heat. This leads to an increase in temperature with altitude in this layer, from -60 degrees at the tropopause to around 5 degrees at the top of the stratosphere.

Because this layer starts out hotter than the top of the tropopause, convection cannot occur. Therefore, you sometimes see cumulonimbus clouds with flat tops (anvil clouds), because the air can no longer rise.

Image of an anvil cloud taken from the ISS over Africa. You can see the distinct flat top of the cloud. (NASA)

Mesosphere

The stratopause separates the stratosphere from this next layer, the mesosphere.

This layer extends from 31 miles to 53 miles above the Earth’s surface.

Gases in the mesosphere are thick, which helps slow meteors entering our atmosphere. This allows them to burn off and creates the beautiful streaks of light we see in meteor showers.

Thermosphere

Between 53 miles and 375 miles above the Earth’s surface, the thermosphere comes after the mesopause.

Temperatures can reach up to 3,600 degrees near the top of the layer as the absorption of ultraviolet rays and X-rays causes this layer to heat up.

However, this layer of the atmosphere would still be very cold for our skin due to the weak atmosphere. There are not enough gas molecules to transmit heat to us.

The ISS orbits the Earth once every 90 minutes. (NASA)

Exosphere

The final outermost layer is the exosphere, which extends from the top of the thermosphere 6,200 miles above the Earth’s surface.

Here gases can escape into space and satellites can orbit the Earth.

A different view of the sky

So the next time you look up into the night sky, remember the different layers you’re looking at.

Each layer comes together to protect us. It contains the oxygen we need to breathe and protects us from ultraviolet solar radiation.

It also creates the pressure needed to give us liquid water and warms our planet just enough for us to live on Earth.

Our team of meteorologists dive deep into the science of weather and break down weather data and information in a timely manner. To see more weather and climate related articles, check out our weather blogs section.

About Lucille Thompson

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