Layers of the atmosphere
The atmosphere is divided up into 5 layers. The higher up you go, the thinner the atmosphere becomes.
You cannot see a separation between the layers but you can feel a difference in temperature. The higher up you go, the colder it becomes; but then something strange happens, it gets hotter again!
Starting from the ground, these are the 5 layers of the atmosphere:
Troposphere: the layer closest to the ground. It is where humans, animals and plants live. It’s also where most of the clouds are found so it has the most water vapour of all. Nearly 80% of the atmosphere is found in the troposphere.
Stratosphere: the layer that is second closest to the ground. This is where the ozone layer is found. The stratosphere has few clouds so there is very little water vapour. Many aeroplanes fly in this layer to avoid the bumpy rides caused by clouds in the troposphere. The stratosphere has low levels of oxygen.
Mesosphere: the middle layer and the coldest layer of all. This is where most meteors from space burn away before they get the chance to reach the Earth. The winds in this layer are very strong.
Thermosphere: a very hot layer where many low lying satellites orbit the Earth. This layer is very important in radio communication.
Exosphere: the top layer which fades into space. It is the ideal place for satellites.
Atmosphere or outer space?
If you’re wondering where outer space starts, then you’re not the only one. Scientists have been trying to come up with an answer for a long time. The truth is there isn’t really a clear answer. Most scientists agree that once you reach 50-80 miles away from the surface of the Earth, you are in outer space.
The damage we cause
The atmosphere can be contaminated with smoke, toxic gases, dust, ash from volcanoes, and salt. One of the biggest causes of contamination is us, humans!
The vehicles we drive and the harmful gases our factories release into the air has made the air dirty, warmed up the planet through global warming and damaged the ozone layer.
The ozone layer protects the planet from the Sun’s radiation, when it is damaged it cannot protect us as well. More and more people are now getting skin cancer because the ozone layer cannot properly absorb the radiation from the Sun.
Did you know?
- The study of the Earth’s atmosphere is called aerology.
- 99% of water vapour in the Earth’s atmosphere is in the troposphere
- There is a layer that overlaps the mesosphere and thermosphere called the ionosphere.
