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The atmosphere, structure and origin
The atmosphere is a thin layer of a mixture of gases that surrounds the earth, with a thickness of 20.000 km, gases remain retained on the planet due to gravitational force. The atmosphere is classified in regions this according to its physical characteristics in: Trophosphere, stratosphere, mesosphere, termosfera, exosphere where the magnetosphere is located.
These layers will be influenced by a series of internal processes and external interactions that can maintain or alter the inherent properties of each of them such as: temperature, chemical activity, incident solar radiation energy, relative properties, pressure and density. 75% of the mass of the entire gas mixture present in the atmosphere is found in the first 11km and, the majority components are the N2, O2 and AR that includes 99.98% of the soda mixture and 0.02% corresponds to a wide variety of minority gaseous compounds. According to the chemical composition, the atmosphere is divided into homosphere that includes 0 to 50 km of altitude, here the most abundant gases are N2, O2, AR, H2O and CO2;And, the heterosphere that goes from 50 km to 10,000 km where the main gases are N2, O2, He and H.
This layer is in direct contact with the Earth, being the closest to the surface. The thickness of this layer is 12 km on average, 9 at the poles and 18 in Ecuador, despite being the thinnest layer of the atmosphere comprises 75% of the total mass, in addition to containing all the water vapor.
The temperature varies with the height decreasing 6.5ºC for every kilometer traveled. It is in this layer where most meteorological phenomena occur that maintains the air in constant agitation producing the movement of both vertical and horizontal air, these air mass movements allow the transport of many materials and also serves to disperse atmospheric pollutants.
The surface climate is changing and this is due to the convention cells that redistribute heat from the sun that reaches the tropics and equator, towards cold areas such as the poles.
The composition of gases in the troposphere is homogeneous in almost all its volume being nitrogen, the majority gas with 78% of the total volume;Oxygen with 21% is the second gas with the highest volume and argon, with 0.9%;The rest of minority gases, but not less important in the chemical reactions that occur in this layer of the atmosphere constitutes 0.1%. In addition, there are solid and liquid particles in suspension, gaseous compounds, volcanic origin, soil erosion, from oceans or forest fires;forming an active part of physical-chemical processes that occur in this layer of the atmosphere, acting as catalysts and helping cloud formation. The limit of the troposphere is known as tropopousa.
Atmosphere layer that extends from 12 km to 50 km altitude, the thermal gradient is invested to 0ºC, due to photochemical reactions that do not allow the rise of air masses making it impossible for meteorological phenomena to occur inthis zone.
It is in the stratosphere where a layer called ozone is located at a height of 25 km, being this important layer so that life can be developed on the planet, serving as a filter of ultraviolet radiation from the sun that are harmful to beings for beingsalive. The gases found in this layer are methane, nitrogen oxides. The limit of this layer is known as stratopousa.
This layer extends from 50 km to 80 km high, another thermal investment decreasing again to 90ºC below zero and the most energy rays that come from the sun are absorbed.
In this layer the composition of the air depends on the height, there is the presence of light gases and a large production of ions and electrons due to the absorption of solar radiation.
The temperature in this layer ascends again due to the absorption of ultraviolet radiation, X -rays, causing the ionization of many species such as O2, N2, it is for this reason that this layer is also known as ionosphere. It is in this area where boreal and southern lights occur, because chemical species interact with the solar wind.
The base of this layer is located about 500-750 km, mostly formed by atoms and oxygen, hydrogen and helium ions. The concentration of ionized particles through the exosphere is increasing until it reaches 2.000 km, where is a huge band of radiation known as Magnetosphere.
Origin and evolution
The composition of the atmosphere that exists today has been the product of hydrosphere interactions, soil and living beings over time.In the beginning the atmosphere was composed of water, carbon dioxide, carbon, nitrogen, hydrogen, methane and ammonia. Similar to that of other internal planets such as Venus and Mars.
Due to the heat generated by the formation of the nucleus, minerals and gases such as helium and hydrogen that escaped the space were released, however, hydrogen is trapped in heavier compounds by the different reactions, gave rise to a primitive atmosphere constituted by methane,ammonia and water.
The primary atmosphere having as the main element of carbon dioxide, molecular nitrogen and water vapor, it is said that they occurred from the oxidation processes of the species appointed above reacted with pre-biological oxygen that could be originated from the photolysis processes of the photolysis processes of theCarbon dioxide and water. These reactions plus the presence of atmospheric oxygen originated the stratospheric ozone layer. This ozone layer allowed to filter the harmful ultraviolet rays for living beings.
It allows us to know how it originated, the composition of the atmosphere, the areas it has and the importance of each area so that it works as an interconnected system allowing to develop life on the planet, functioning as a protective shield to the solar radiation emitted by thesun. In case the atmosphere is a fine layer that covers the earth, fragile, delicate, dependent on any anthropogenic activity that develops within it, changing in time both in its composition and structure.
For us as future engineers in environmental management and conservation it is pertinent to know how atmosphere works, of all physical, chemical and biological processes that develop in it, in order to be able to make proposals that help improve and preserve the atmosphereand that it is propitious for the development of life as we know it. At present it is in serious problems by not being ableThere it exists.
- Environmental pollution: a vision from chemistry – María Nieves González Delgado, Carmen Orozco Barrenetxea, Antonio Pérez Serrano, Jose Marcos Alfayate Blanco, Francisco J. Rodriguez Vidal
- Google books.”Https: // Books.Google.com.EC/Books?id = nuooox-8knyuc & printsec = frontcover & dq = inauthor:%22maría+Nieves+González+Delgado%22 & hl = es & sa = x & ved = 0ahkewjg__bzuq7lahwxrfkkhvp1ahuq6aeimdab#v = onepage & q & f = fals (October 21, 2019).
- Martins Nogueira, João Vianey. 2013. "Atmospheric pollution.”Journal of Chemical Information and Modeling 53 (1): 1689–99.