Layer of air surrounding the earth:
The layer of air surrounding the Earth is called the atmosphere. It is composed of various gases and extends from the surface of the Earth to outer space. Here is a detailed explanation of the Earth's atmosphere:
1. Composition:
- The atmosphere is primarily composed of nitrogen (78%) and oxygen (21%).
- Other gases present in smaller amounts include carbon dioxide, water vapor, and various trace gases.
2. Layers:
- The atmosphere is divided into different layers based on temperature changes with altitude.
- The layers, from closest to the Earth to farthest, are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
3. Troposphere:
- The troposphere is the lowest layer of the atmosphere, extending from the Earth's surface up to about 8-15 kilometers.
- It is where weather occurs and contains most of the Earth's clouds, air pollutants, and water vapor.
4. Stratosphere:
- The stratosphere lies above the troposphere and extends up to about 50 kilometers.
- It contains the ozone layer, which absorbs and filters out a significant amount of the Sun's ultraviolet radiation.
5. Mesosphere:
- The mesosphere is above the stratosphere and extends up to about 85 kilometers.
- It is the layer where meteors burn up upon entering the Earth's atmosphere.
6. Thermosphere:
- The thermosphere is above the mesosphere and extends up to about 600 kilometers.
- It is characterized by high temperatures due to the absorption of solar radiation.
7. Exosphere:
- The exosphere is the outermost layer of the atmosphere, transitioning into space.
- It is where the atmosphere gradually thins out, and its gases dissipate into the vacuum of space.
Overall, the atmosphere plays a crucial role in protecting life on Earth by regulating temperature, providing oxygen, and shielding us from harmful radiation.