What Is the Stratosphere?

The Stratosphere

The stratosphere extends from about 12 to 50 km upwards. It’s sandwiched between the troposphere below and the mesosphere above.

The major highlights of the stratosphere include:

Ozone (O₃) in the stratosphere absorbs harmful ultraviolet radiation from the sun.
The absorbed ultraviolet radiation from ozone causes the temperature in the stratosphere to rise.
About 10% of the atmospheric mass is in the stratosphere. But the air is still so thin that you’d freeze in an instant.
Airplanes use the stratosphere when they travel from west to east because it gives an extra push on their tail.

Here are more details on the stratosphere and its influences on Earth.

Where is the stratosphere in the atmosphere?

The stratosphere is the second atmospheric layer from the ground level. It sits above the troposphere and is directly below the mesosphere.

The stratosphere is bounded by the tropopause and stratopause. It’s characterized by a highly stable temperature gradient that cools from top to bottom.

Although variations in altitude exist, it’s roughly between 12 to 50 km above sea level. Specifically, the geography and time of season influence the lower bound.

For example, the tropics have an average troposphere height of 18 km. But the polar regions have a troposphere upper bound altitude of about 6 km.

Is ozone concentrated in the stratosphere?

The stratosphere is filled with ozone gas, which is the three-atom form of oxygen. And ozone is concentrated at about 25 km. It’s in the stratosphere where O₂ may be photolyzed by solar ultraviolet radiation to form the ozone layer.

Any high-frequency radiation such as x-rays, ultraviolet, and gamma rays are harmful to living tissues. This can cause cells to become cancerous.

This protective layer is essential for life because it absorbs ultraviolet radiation. Without ozone in the stratosphere, ultraviolet light from the sun would damage all living things on the planet.

What is air temperature like in the stratosphere?

Ozone is the main reason why temperature increases in the stratosphere. It’s at this 25 km concentrated ozone mark where ultraviolet radiation is absorbed.

Consequently, the absorbed light causes air temperature to rise. This is why as you move upwards in the stratosphere, air temperature increases.

Then, air temperature continues to rise until it hits the mesopause. Finally, maximum heating occurs when it reaches the top part of the stratosphere.

The environmental lapse rate (ELR) measures how much temperature decreases with height. But because air temperature increases up to the stratopause, the lapse rate is negative in the stratosphere.

Does water vapor exist in the stratosphere?

If you look at water vapor, 99% is found in the troposphere. This is why most weather takes place here.

Weather patterns dump rain moving water vapor through the troposphere. Consequently, this moisture availability influences floral and fauna in various environments.

But water vapor can scarcely survive by vertically moving into the stratosphere. Clouds initially form in the troposphere. But tall cumulonimbus can ascend through the tropopause reaching far into the stratosphere.