From the ground up, the atmosphere is divided into four layers by the way its temperature changes with height:
- the troposphere, where the temperature falls with height and where almost all the weather happens; its top is the tropopause;
- the stratosphere, where the temperature rises with height, up to about ;
- the mesosphere, where the temperature falls again, up to about ;
- the thermosphere, where the very thin air gets hotter and hotter with height.
示例
Example 23.4 (An airliner at cruising height)
An airliner cruises at , near the tropopause. On the profile, the temperature there is about . With the lapse rate: from at sea level, the air cools by degrees, which gives . On the pressure curve, the pressure is about , less than a quarter of the pressure on the ground: the cabin has to be pressurised.