Question: what are the four layers of the atmosphere and their characteristics?
Answer: The Troposphere. This is the lowest part of the atmosphere - the part we live in. ... 
The Stratosphere. This extends upwards from the tropopause to about 50 km. ... 
The Mesosphere. The region above the stratosphere is called the mesosphere. ... 
The Thermosphere and Ionosphere. ... 
The Exosphere. ... 
The Magnetosphere.