Stratosphere: Definition, Discovery, Characteristics, Ozone layer, Functions

What is the Stratosphere?

The stratosphere is the stable and stratified layer in Earth's atmosphere. The troposphere, the lowest layer, is immediately underneath the stratosphere, and the mesosphere is the next layer higher than the stratosphere.

5 Main Layers of the Atmosphere

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Discovery of Stratosphere

In 1902, French scientist Léon Teisserenc de Bort and German scientist Richard Assmann independently discovered a stable temperature layer in the atmosphere at an altitude of 11-14 kilometers. This discovery, based on balloon data, laid the groundwork for our understanding of the lower stratosphere.

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Main Characteristics of the Stratosphere

• The stratosphere contains the very crucial ozone layer. The Earth is shielded from the sun's ultraviolet radiation (UV) by the ozone layer. In actuality, the majority of the UV energy that the sun emits is absorbed by the ozone layer. The sustainability of life on Earth will be threatened in the absence of a fully functional Ozone Layer.
• The stable temperature layers in the stratosphere prevent air mixing and create a calm environment. This makes the lower stratosphere ideal for commercial airplanes as it avoids turbulence and drag experienced in the lower atmosphere. The air density at the top of the stratosphere is much thinner than the sea level.
• The stratosphere is affected by waves and tides that move energy around the atmosphere. These can cause air flow and even heat in certain areas. Additionally, a rare electrical phenomenon called blue jets, similar to lightning can occur at the bottom of the stratosphere.

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What is the Ozone layer?

The ozone layer is an essential component of Earth's stratosphere, shielding it from damaging UV light. Ozone absorbs UV light, keeping it from reaching the Earth's surface and causing harm to living things. However, the ozone layer is diminishing due to substances such as chlorofluorocarbons (CFCs), which degrade ozone molecules. This weakening is most noticeable at the poles, resulting in what are generally referred to as "ozone holes." People became aware of the consequences of ozone depletion in the 1970s, and many governments and businesses took steps to limit the use of CFCs. As a result, the ozone layer is gradually recovering.

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Functions of the Stratosphere

• The stratosphere houses 19% of Earth's greenhouse gases and 90% of the ozone layer, which protects us from harmful UV radiation.
• There is relatively little water vapor in the air and the stratosphere is quite dry. Because of this, there are not many clouds in this layer; instead, most clouds originate in the lower, more humid troposphere.
• The ozone layer is naturally created by sunlight splitting oxygen molecules and then reforming them into ozone.

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What is the difference between the troposphere and the stratosphere?

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Do planes fly in the stratosphere?

Indeed, commercial airliners normally fly at altitudes of 9-12 km (30,000-39,000 ft), which are in the lower stratosphere in temperate latitudes. This altitude provides various advantages to airlines. By lowering temperatures and air density at the tropopause, it first increases fuel economy by lowering drag on the aircraft. This maintains the required lift but speeds up the airplane's flight. Additionally, smoother flights are achieved by elevating airplanes above the turbulent troposphere's weather.