We explain what the atmosphere is, where it is located and how it is composed. Also, what are its characteristics and contamination.
The Earth’s atmosphere has a combination of gases suitable for life.
What is the Atmosphere?
The atmosphere is the different layers of gases that cover the celestial starsattracted by its gravity until they stabilize around it, reaching different heights. Its chemical composition can be very varied and, in the case of our planet Earth, it contains the air we breathe and the gases that allow the existence of life.
The Earth’s atmosphere is known as the Earth’s atmosphere and this article will focus on it. The Earth’s atmosphere is unique in its composition in the Solar System.since it contains the appropriate combination of gases important for life to take place on the planet’s surface.
In the atmosphere the temperature and pressure conditions that allow the hydrological cycle are giventhere is the ozone layer that shields the planet from solar radiation, and friction occurs that reduces meteorites coming from space to dust.
See also: Water cycle.
Location of the atmosphere
75% of the gaseous mass of the atmosphere is located in the first 11 km of elevation.
The Earth’s atmosphere It is found around the surface of the planetextending from the ground to about 10,000 kilometers around the planet, in various layers of more or less uniform gases.
75% of its gaseous mass is located in the first 11 km of elevation from the sea surface, and as it gains height it also gains an important measure of pressure.
Composition of the atmosphere
Nitrogen is the most abundant element in the atmosphere.
The composition of the atmosphere has varied throughout the history of the planet, especially since the appearance of living beings, which consume certain gases and produce others. However, its composition is mostly nitrogen (78%) and oxygen (21%)along with other important gases such as ozone, hydrogen, carbon dioxide, argon and other noble gases. It also contains a significant presence of water vapor (H2O).
Regions of the atmosphere
Two regions are commonly distinguished in the Earth’s atmosphere, which are:
- Homosphere. Its name comes from its constant and regular composition, which occupies the first 100 km of the atmosphere from the ground. All the gases necessary for life are found there in different proportions.
- Heterosphere. Its name comes from the fact that it is stratified into different layers of gases, which vary according to height and pressure:
- 80-400 kilometers high: molecular nitrogen (N2).
- 400-1100 kilometers altitude: atomic oxygen (O).
- 1100-3500 kilometers altitude: helium (He).
- 3500-10,000 kilometers altitude: hydrogen (H).
Layers of the atmosphere
In the stratosphere, oxygen is transformed into ozone by ultraviolet rays.
The Earth’s atmosphere is usually divided into layers, which respond to its variation in temperature and pressure, thus forming a scale called atmospheric thermal gradient. These layers would be:
- Troposphere. The lower layer, which goes from the first 6 to 20 kilometers of height. This is the layer where climatic phenomena occur and the end of the layer is at a temperature of -50 °C.
- Stratosphere. It ranges from 20 to 50 kilometers high, arranged in various strata or phases of air (hence its name). In it, oxygen is transformed into ozone by ultraviolet rays, a process that generates heat, which is why temperatures increase in this layer (-3 °C).
- Ozonosphere. In reality, it is a phase of the stratosphere, where the greatest amount of ozone is produced and, consequently, the well-known ozone layer is found that protects the planet from the direct impact of the sun’s rays, absorbing more than 95%. thereof.
- Mesosphere. It extends between 50 and 80 kilometers in height, and contains only 0.1% of the atmospheric air mass. It is the coldest zone in the entire atmosphere: it reaches temperatures of up to -80 °C.
- Ionosphere. Also called the thermosphere, it ranges from 90 to 800 kilometres in height, and the temperature increases with altitude, depending on the presence of sunlight. Temperatures of 1500 °C and even higher have been recorded there.
- Exosphere. The outer layer of the atmosphere, which begins at 800 kilometers and ends at 10,000 kilometers. This is where atoms escape into space, and it is the transit zone between our planet and outer space.
Greenhouse effect
The greenhouse effect is essential for the preservation of Earth’s heat.
The greenhouse effect is known as the presence of atmospheric gases such as carbon dioxide that form a dense layer in the atmosphere and prevent the escape of Earth’s heat (similar to the walls of a greenhouse). This effect It is vital for the preservation of the earth’s heatessential for life.
More in: Greenhouse effect.
Importance of the atmosphere
The atmosphere performs vital functions for the stability of the planet, as we have said. Not only It allows the perpetuation of biochemical cycles by supplying the essential gasesbut also prevents the escape of heat into outer space, shields us from meteorites (friction with the air disintegrates them) and solar radiation. Without it we would be exposed to the elements of space and dramatic temperature variations between day and night.
Magnetosphere
The magnetosphere prevents the passage of solar winds and other forms of solar radiation.
The magnetosphere is the name given to the region of the atmosphere in which the planet’s magnetic field is noticeable. This is generated by its rotation movement and by its cast iron heart, which acts like a dynamo. This field is also vital to prevent the solar wind and other forms of electromagnetic radiation from entering our planet. When this occurs, the so-called “auroras” occur.
It may be useful to you: Terrestrial magnetism.
Space travels
The takeoff of a rocket can cause heating as it passes through the atmosphere.
Overcoming the resistance of the atmosphere is one of the main challenges of space travel, as well as overcoming gravity in a sustained manner. The friction that a space shuttle suffers during takeoff in the initial layers of the atmosphere can generate heating, deviation of the trajectory and even breakage of materials. However, once in the outer layers, the low density of gaseous material will allow movement in a much gentler manner.
Origin of the atmosphere
The origin of the atmosphere is often attributed to the presence of gases originating from the early stages of the Solar Systemwhich were trapped in the planet’s gravity, as well as the degassing of the Earth’s crust as it cooled. Added to this is the ice and water from the impact of comets on Earth, and then the appearance of gases typical of organic life.
Air pollution
The gas produced by factories is one of the worst atmospheric pollutants.
The atmospheric pollution occurs mainly in the form of gases, which not only enhance the greenhouse effect but also corrode the ozone layer, allowing solar radiation to enter and increasing the temperature of the planet. To this must be added the suspension of toxic particles in the lower layers of the atmosphere, which can lead to acid rain.
Continue in: Air pollution.