Moving up from the surface, the stratosphere is the second layer of the Earth's atmosphere, beginning between 5 and 10 miles (26,000 to 53,000) feet up. There is very little water vapor present or cloud formation occurring in the stratosphere, but this layer holds about 19 percent of the total gas in the atmosphere.
The stratosphere layer continues up to about 31 miles, before the beginning of the mesosphere. The stratospheric layer holds the ozone in the atmosphere, protecting the surface by absorbing harmful ultraviolet radiation from the sun. It is because of the absorption of these UV rays that the temperature in the stratosphere increases with altitude, from a minimum of about minus 60 degrees Fahrenheit at the bottom up to about 5 degrees Fahrenheit near the top of the layer. Also because of this phenomenon, there are no upward moving convection currents in the stratosphere, as the warmer air is on top of the cooler air. This lack of air movement is the reason why planes fly in the lower stratosphere, where there is minimal turbulence. However, at the top of the stratosphere, the air is about 1,000 times thinner than it is at sea level, restricting the use of aircraft in the upper regions.