1st PART



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.

The stratosphere is separated from the mesosphere, which lies above it, by the stratopause.

This chart is produced and update with data of the SSU/MSU

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