STRATOSPHERIC COMPOSITION
The
stratosphere is the second main layer of the
atmosphere. It lies above the troposphere
and is separated from it by the tropopause.
It fills in the region of the atmosphere about
7,45 to 31,06 miles (12 to 50 km), while its
lower limit is higher at the equator and lowest
at the poles.
The
stratosphere defines a layer in which the temperatures
rise with increasing altitude. At the top of
the stratosphere the thin air can reach temperatures
near 32°F (0°C). This rise of temperature
is caused by the absorption of ultraviolet (UV)
rays of the sun by the ozone layer. Such a temperature
profile creates very stable atmospheric conditions,
and the stratosphere lacks the turbulence of
the air that is so prevalent in the troposphere.
Accordingly, the stratosphere is almost completely
free of clouds or other forms of weather.
The
stratosphere provides some advantages for the
flight of long distance because it is above
the stormy weather and strong, steady and horizontal
winds.