The stratosphere is one layer of the atmosphere, located above the troposphere and below the mesosphere. Because it absorbs a large amount of ultraviolet radiation, the temperature in this layer is cooler at the bottom and warmer at the top.
This is exactly the opposite of the troposphere, which is warmer at the bottom and cooler at the top. It is precisely because of this that the stratosphere is more stable and lacks conventional convection activities and related airflow.
Due to this characteristic of the stratosphere, it is also known as the isothermal layer, where temperature and airflow are relatively stable, making it an ideal place for aircraft flight.
Most of the world's commercial airliners cruise in the stratosphere to avoid the variable weather and airflow within the troposphere, thereby maintaining flight stability.
