What is the stratosphere?
|The stratosphere is the second major atmospheric layer above the
troposphere, extending in altitude from about 8 to 30 miles high.
No weather occurs in the stratosphere. The statosphere contains over 15% of the total mass of the atmosphere, and is
where the ozone layer is located.
Air temperature slowly increases with height in the stratosphere, in contrast with the troposphere
where the temperature rapidly decreases with height. This unusual temperature structure is
caused by absorption of sunlight by ozone.
All weather stops at the top of the
troposphere (called the tropopause), and the stratosphere is essentially cloud-free.
If you see a tall thunderstorm with an anvil cloud,
it is likely that the anvil cloud has reached the bottom of the stratosphere. At that level,
atmospheric convection stops because rising cloudy
air parcels are no longer warmer than their environment, since stratospheric air is relatively warm.
|AIRPLANES NOT ALLOWED Very few airplanes can fly as high
as the stratosphere because the air is so thin that there is not enough lift to keep the aircraft
supported. Some spy planes do fly in the lower stratosphere, however, such as the U-2 and the SR-71. Another exception to this is in
cold winter air masses, when the stratosphere can lower to an altitude where airplanes can fly.
(page last updated 12/15/2019)