The gas shell of our planet, which protects it from harsh cosmic influences from the outside, is called the atmosphere. Without it, life on Earth would be impossible. Its thickness is several thousand kilometers, and the atmosphere consists of several layers. Which one is called the troposphere?
Definition
What is the troposphere and what is its thickness? All changes that occur in this layer of the atmosphere have a significant impact on weather conditions on Earth. The troposphere is the lowest layer of the atmosphere. It makes up about 75% of its total mass. The troposphere contains 99% of the total mass of atmospheric aerosols and water vapor.
The word is derived from the ancient Greek language. It consists of two roots - “tropos” (rotation, change) and “sphere” (ball). The troposphere is the lower layer of the gas shell, which most closely interacts with the upper layers of our planet - the hydrosphere and lithosphere. It is a constant exchange of moisture, heat, as well as chemical elements.
The properties
Those interested in what the troposphere is, it will be interesting to know that its thickness is not the same. In temperate latitudes, it does not exceed 17 km, in the tropics - 20 km. Near the poles of the globe, it is no more than 10 km. The lower layer of the troposphere is boundary, and its depth is from several hundred meters to 2 km.
It is greatly influenced by air currents on the surface of the planet, the shape of the land, as well as the circadian rhythm. After every 100 m rise in the tropospheric layer of the gas envelope, the air temperature in the troposphere drops by an average of 0.65 degrees Celsius. The total thickness of the atmosphere does not exceed 25 thousand km.
As the density of air decreases, the atmosphere without any clear boundary passes into outer space. Moreover, the upper boundary of the gas shell ends at the level of 20 thousand km. The lower boundary of the troposphere passes along the surface of the planet.
The composition of the troposphere
The ground layer consists of two important chemical elements - nitrogen and oxygen. The nitrogen content is 78% of the entire gas envelope of the Earth; oxygen - 21%. The most important role in maintaining life on our planet is played by water, oxygen and carbon dioxide. An important role in the process of plant nutrition is played by the nitrogen cycle. Water vapor is also an important component, due to which the required temperature level is maintained. Steam enters the troposphere due to evaporation from the surface of the ocean.
Nitrogen, a large proportion of which is contained in the atmosphere, serves as a kind of diluent for oxygen. We can say about carbon dioxide that its content in the gas shell of the planet is quite variable. Carbon dioxide enters the troposphere from various sources - volcanic eruptions, from organisms, from the soil, biological decay products, etc. Despite the low content of this gas in the troposphere, its role in maintaining life is extremely important, because plants need it for photosynthesis .
Also of great importance for the troposphere is dust, most of which rises from the continents. It consists of particles of various minerals, salts, spores and microorganisms. Clouding of the atmosphere due to dust weakens the planet’s protection from solar radiation.
Processes in the troposphere
The layer following the troposphere is the stratosphere. The atmosphere also includes other layers - the mesosphere, exosphere and thermosphere. However, the troposphere, more precisely, its lower layer, is the most important layer for maintaining life on Earth. The two layers are separated by a tropopause - a thin transitional section where the temperature ceases to decrease in proportion to the increase in height.
The biosphere, as well as most of the atmospheric air, is located in the troposphere. It is here that various types of clouds form, weather fronts and air masses, cyclones and anticyclones form. In the troposphere is the entire system of air currents. As a result of condensation processes, clouds form, causing precipitation in the form of rain, hail or snow.
Water transitions from one state to another are carried out precisely in the troposphere. At the surface of the planet, air pressure is higher than in the upper layers. The processes taking place in this layer of the atmosphere affect the climate and weather conditions.
Atmosphere value
What is the role of the gas shell of our planet? Firstly, in its lower layer - namely, in the troposphere - almost all air reserves are concentrated. Thanks to these reserves, living organisms are able to breathe. The importance of the atmosphere for life on Earth cannot be overestimated - because without air our planet would be uninhabited, like other celestial bodies in the solar system. And in the upper part of the gas shell is the ozone layer, which protects the Earth from cosmic influences. Thanks to him, dangerous cosmic radiation does not reach our planet.
Ground layer
Those who study what the troposphere is, should know about its lowest layer, which is called the surface. It contains a large amount of dust, as well as various volatile microorganisms. In the surface layer, daily fluctuations in temperature, as well as air humidity, are well pronounced. With increasing altitude, wind speed increases. In this layer, a vertical distribution of air temperature is observed.
What is the troposphere and what is its significance for all life on Earth, every student knows. After all, it is its surface layer that represents the habitat for all living organisms. A great influence on the composition and structure of the surface layer of the troposphere is exerted by gases from the faults of the lithosphere, as well as the existence of life.