The Earth's atmosphere is composed of several distinct layers, each characterized by different temperatures, composition, and behaviors. These layers, from the surface of the Earth upward, are:
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Troposphere:
- Extent: This is the lowest layer, extending from the Earth's surface up to about 8 to 15 kilometers (5 to 9 miles) high, depending on latitude and weather conditions.
- Characteristics: The troposphere contains approximately 75% of the atmosphere's mass and the majority of its water vapor. Weather phenomena, such as clouds, rain, and storms, occur in this layer. Temperature generally decreases with altitude.
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Stratosphere:
- Extent: This layer extends from the top of the troposphere to about 50 kilometers (31 miles) above sea level.
- Characteristics: The stratosphere contains the ozone layer, which absorbs and scatters ultraviolet solar radiation. Unlike the troposphere, temperature in the stratosphere increases with altitude due to the absorption of radiation by the ozone.
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Mesosphere:
- Extent: The mesosphere stretches from 50 kilometers (31 miles) to about 85 kilometers (53 miles) above the Earth.
- Characteristics: This layer is where most meteors burn up upon entering the Earth’s atmosphere. Temperature decreases with altitude, making it the coldest atmospheric layer.
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Thermosphere:
- Extent: The thermosphere extends from about 85 kilometers (53 miles) to 600 kilometers (373 miles) above the Earth.
- Characteristics: In this layer, temperature increases significantly with altitude, reaching up to 2,500 degrees Celsius (4,500 degrees Fahrenheit) or higher due to the absorption of highly energetic solar radiation. The thermosphere is also where the auroras occur and is home to the International Space Station.
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Exosphere:
- Extent: This is the outermost layer of the atmosphere, starting at about 600 kilometers (373 miles) and extending out to about 10,000 kilometers (6,200 miles).
- Characteristics: The exosphere is where atmospheric particles are extremely sparse, and it gradually fades into outer space. These particles can travel hundreds of kilometers without colliding with one another. Satellites orbit within this layer.
Each of these atmospheric layers plays a crucial role in maintaining life on Earth and regulating the planet's climate and weather patterns.