Earth's atmosphere - a gaseous envelope of the planet.By the way, these shell have almost all celestial bodies, from planets in the solar system to large asteroids.The composition of the atmosphere depends on many factors - the size of the celestial body, its speed, weight and other set parameters.But only the shell of our planet contains components that allow us to live.
Earth's atmosphere: a brief history of the origin
believed that at the beginning of its existence, our planet had no gas shell.But the young, newly formed celestial body is constantly evolving.Primary Earth's atmosphere was formed as a result of continuous volcanic eruptions.This is so for many thousands of years around the earth sheath formed of steam, nitrogen, carbon, and other elements (except oxygen).
Since the amount of moisture in the atmosphere is limited, it turned into a surplus of rainfall - so formed seas, oceans and other water bodies.In the aquatic environment appeared and developed the first organisms that populate the planet.Most of them belong to the vegetable organisms produce oxygen through photosynthesis.Thus, the Earth's atmosphere began to fill this vital gas.As a result, the cluster was formed with oxygen and the ozone layer, which protects the planet from the damaging effect of UV radiation.These factors and created the conditions for our existence.
structure of the Earth's atmosphere
As you know, the gaseous envelope of the planet consists of several layers - this is the troposphere, stratosphere, mesosphere, thermosphere.It is impossible to draw clear boundaries between these layers - it all depends on the season and latitude region of the planet.
troposphere - the lower part of the gas shell, which reaches an average of 10 to 15 kilometers.It is here that concentrated most of the air.By the way, here it is all the moisture and form cloud.Due to the oxygen content of the troposphere supports the livelihoods of all organisms.Furthermore, it is of crucial importance in the formation of weather and climate terrain - there are formed not only clouds, but also wind.The temperature decreases with altitude.
Stratosphere - troposphere starts from and ends at a height of 50 to 55 kilometers.Here, the temperature increases with height.This part of the atmosphere substantially free of water vapor, but is ozone.Sometimes you can notice the formation of a "pearl" clouds, which can be seen only at night - is that they are represented strongly condensed water droplets.
mesosphere - reaching up to 80 kilometers.In this layer, you will notice a sharp drop in temperature as it moves upward.There are also highly developed turbulence.By the way, in the mesosphere are formed so-called "noctilucent clouds", which are composed of small ice crystals - they can be seen only at night.Interestingly, at the upper boundary of the mesosphere is almost no air - it is 200 times smaller than near the earth's surface.
thermosphere - a top layer of the Earth's gaseous envelope in which to distinguish between the ionosphere and the exosphere.Interestingly, with the height of the temperature here rises very sharply - at a height of 800 kilometers from the earth's surface, it is more than 1,000 degrees Celsius.The ionosphere is characterized by strong liquefied air and high content of active ions.As for the exosphere, this part of the atmosphere smoothly into interplanetary space.It is worth noting that the thermosphere does not contain air.
can be seen that the Earth's atmosphere - a very important part of our planet, which is a decisive factor in the emergence of life.It provides livelihoods, support the existence of the hydrosphere (water shell of the planet) and protects against ultraviolet radiation.
