The Earth's atmosphere is a key element for life on our planet. It not only provides us with the oxygen that we breathe, but also protects us from the solar radiation and helps regulate the temperatureThanks to its composition and structure, we enjoy a stable climate and the conditions necessary for ecosystem development.
In this article, we will explore in depth the layers of the atmosphere, its chemical composition and its importance for life on Earth. Each of these layers has unique characteristics and plays a fundamental role in the protection and conservation of our planet. To better understand this fascinating topic, you can read about the composition of the atmosphere.
What is the atmosphere?
The atmosphere is the gaseous envelope that surrounds the Earth and is held together by the gravitational pull. Its composition has evolved over millions of years, becoming the balance of gases we know today. If you want to learn more about the atmosphere formation, we recommend you continue reading.
Its function is vital: it protects us from the cosmic radiation, allows the existence of hydrological cycle and contributes to the distribution of heat on the planet. Without the atmosphere, life as we know it would not be possible.
Composition of the atmosphere
The atmosphere is composed of a mixture of gases, mainly:
- Nitrogen (N₂): Represents the 78% from the air and is essential for biological cycles.
- Oxygen (O₂): It constitutes the 21% and is essential for the respiration of living beings.
- Argon (Ar): With a 0,93%, is an inert gas with no direct impact on life.
- Carbon dioxide (CO₂): Represents only the 0,04%, but it is key to photosynthesis and the greenhouse effect.
- Other gases: Such as neon, helium, methane and water vapor, in minimal proportions.
These gases are not distributed evenly throughout all layers of the atmosphere. As we ascend, the composition tends to change, with certain gases predominating at different altitudes. To better understand how temperature varies with altitude, you can read about the temperature variation.
The layers of the atmosphere
The atmosphere is divided into several layers based on temperature variations with altitude. Each layer has specific characteristics and plays a fundamental role in protecting the planet.
Troposphere
Is the lowest layer of the atmosphere and the most important for life. It extends from the Earth's surface to approximately 10-15 km altitude. This is where most of the atmospheric gases are found, and where most meteorological phenomena, such as rain, storms, and winds, occur.
Stratosphere
Located between the 15 and 50 km altitude, the stratosphere is known to host the ozone layer, which protects the Earth from the sun's ultraviolet rays. In this layer, the temperature increases with altitude due to the absorption of UV radiation by ozone. For more information on how this layer behaves, visit our article on the structure of the atmosphere.
Mesosphere
It is among the 50 and 85 kmIt is the coldest layer of the atmosphere, with temperatures that can drop to -80 ° CIn this region, meteorites often disintegrate when they come into contact with air friction.
Thermosphere
Since the 85 to 500 km, the thermosphere is a layer where the temperature increases again, reaching the 1.500°C. This is where the Aurora borealis and the orbits of are found satellites and International Space StationYou can find more about this phenomenon in the article on the aurora boreal.
Exosphere
It is the outermost layer of the atmosphere, extending from the 500 km until the 10.000 km altitude. In this region, the gases are highly dispersed and the transition to outer space is gradual.
Importance of the atmosphere
The atmosphere plays a fundamental role in regulating the climate and protecting living beings. Its most important functions include:
- Protection against solar radiationThe ozone layer blocks most harmful UV rays.
- Thermal regulation: It helps maintain a stable temperature on Earth through the greenhouse effect.
- Allows breathing: Contains the oxygen necessary for animal and plant life.
- Facilitates the water cycle: The troposphere allows for the evaporation, condensation and precipitation of water.
The atmosphere is a key element for life on Earth. It protects us from the dangers of space, allows for climate development, and provides the oxygen needed for breathing. To explore more about the importance of the atmosphere, you can visit our article on the GreenhouseEach of its layers contributes uniquely to the planet's balance, ensuring favorable conditions for the existence of living beings.
