what is the atmosphere

What is the atmosphere and its layers?

We are always talking about air pollution, gases that are released from vehicles and industries, and global warming and climate change. However, there are many people who do not know what is the atmosphere, what are its characteristics, layers and how important it is.

For this reason, we are going to dedicate this article to telling you what the atmosphere is, what its beds are and how important they are for life on the planet.

what is the atmosphere

what is the atmosphere

The atmosphere is a uniform layer of gas concentrated around a planet or celestial body and held in place by gravity. On some planets that are made mostly of gas, this layer can be particularly dense and deep.

The Earth's atmosphere is located about 10.000 kilometers from the Earth's surface and houses the gases necessary to maintain a stable planetary temperature and allow life to develop in different layers. The airflow that exists in it is closely related to the hydrosphere (the planetary water collection), and they influence each other.

Our atmosphere can be divided into two large regions: the homogeneous layer (the lower 100 kilometers) and the heterogeneous layer (from 80 kilometers to the outer edge), the first region is more diverse and homogeneous according to the types of gases that compose it . each region Qualitative, and stratified and differentiated in the second.

The origin and evolution of the atmosphere can be traced back to the early stages of the Earth, in which a thick layer of primordial gas remained around the Earth, composed mainly of hydrogen and helium from the solar system. However, the gradual cooling of the Earth and the appearance of life altered the atmosphere and altered its content to the levels we know today through processes such as photosynthesis and chemical synthesis or respiration.

Key features

planet Earth

Earth's atmosphere is made up of various types of gases, whose highest percentages of mass are concentrated in the first 11 km of altitude (95% of the air is in its initial layer), with an approximate total mass of 5,1 x 1018 kg.

The main gases that compose it (in a homogeneous sphere) are nitrogen (78,08%), oxygen (20,94%), water vapor (between 1% and 4% at surface level) and argon (0,93%). However, other gases are also present in small quantities, such as carbon dioxide (0,04%), neon (0,0018%), helium (0,0005%), methane (0,0001%), etc.

For its part, the heterosphere is made up of different layers of molecular nitrogen (80-400 km), atomic oxygen (400-1100 km), helium (1100-3500 km) and hydrogen (3500-10.000 km). Atmospheric pressure and temperature decrease with altitude, so the outer shell is cold and thin.

Layers of the atmosphere

Earth's atmosphere is made up of the following layers:

  • The initial layer in contact with the earth's surface, where most of the atmospheric gases have accumulated. It reaches an altitude of 6 kilometers at the poles and 18 kilometers in the rest of the earth, and it is the warmest of all the formations, although its outer limit temperature reaches -50°C.
  • It varies in height from 18 to 50 kilometers and is distributed in several gaseous layers. One of them is the ozone layer, where solar radiation affects oxygen to form ozone molecules (O3), known as the "ozone layer". This process generates heat, which is why stratospheric temperatures have risen significantly to -3°C.
  • The middle atmosphere, 50 to 80 km high, It is the coldest part of the entire atmosphere, reaching -80°C.
  • The ionosphere or thermosphere. Its altitude varies from 80 to 800 kilometers, the air is very thin, and the temperature fluctuates greatly depending on the intensity of the sun: its temperature can reach 1.500 °C during the day and drops sharply at night.
  • The outer layer of the atmosphere has between 800 and 10.000 kilometers high, relatively indeterminate, just a transition between the atmosphere and outer space. There, the escape of lighter elements from the atmosphere, such as helium or hydrogen, takes place.

ozone layer of the stratosphere

importance of the atmosphere

The ozone layer is a layer that surrounds the earth and prevents the sun's rays and ultraviolet rays from reaching living beings. The area of ​​the earth's stratosphere that contains the highest concentrations of ozone is called the ozone layer or ozone layer. This layer is found between 15 and 50 kilometers above sea level, it contains 90% of the ozone in the atmosphere and absorbs between 97% and 99% of ultraviolet radiation high frequency (150-300nm). It was discovered in 1913 by physicists Charles Fabry and Henri Bison.

The British meteorologist GMB examined its characteristics in detail. Dobson developed a simple spectrophotometer that can be used to measure stratospheric ozone at the Earth's surface. Between 1928 and 1958, Dobson established a global network of ozone monitoring stations that is still in operation today. The Dobsonian unit is the unit of measurement for the amount of ozone, which is named after him.

The importance of the atmosphere

The atmosphere plays a vital role in protecting the planet and life. Its density deflects or attenuates the form of electromagnetic radiation from space, as well as meteorites and objects that might eventually hit its surface, most of which dissolve on entry due to friction with the gas.

On the other hand, the ozone layer (ozone layer) is located in the stratosphere, the accumulation of this gas prevents direct solar radiation from entering the earth's surface, thus keeping the Earth's temperature stable. At the same time, a large amount of gas prevents heat from spreading rapidly through space, which is known as the "greenhouse effect".

Finally, the atmosphere contains the gases necessary for life as we know it and plays a vital role in perpetuating the water cycle of evaporation, condensation and precipitation of water.

I hope that with this information you can learn more about what the atmosphere is and its characteristics.

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