How is the atmosphere formed? How the atmosphere is formed

Causes of the formation of the atmosphere:

The Earth's atmosphere is the formation of an atmosphere of thousands of kilometers under the gravitational pull of the earth, when a large amount of gas gathers around the earth. The density of the gas becomes thinner and thinner as the height above the ground increases. Sounding rockets still found a rarefied atmosphere at an altitude of 3,000 kilometres, and it is suggested that the upper limit of the atmosphere may extend to about 6,400 kilometres above the ground.

The formation of the atmosphere is related to the formation of the earth and the earth's crust on the one hand, and partly to the emergence of animals and plants. It is not formed in isolation. Through the comparison of the atmospheric detection results of some planets, it can be seen that the atmospheres on each planet are in the development stage of Pifeng:

This is useful for understanding the formation of the Earth's atmosphere. But the theory of the formation of the actual atmospheric officer is more severe.

It is foolish to ask people to make further explorations.

Layers of the atmosphere:

1. Troposphere: The troposphere is the lowest layer of the atmosphere, the thickness (8 17 km) varies with the season and latitude, the average temperature decline rate with the increase of altitude is km, there are convection and turbulence, weather phenomena and weather processes mainly occur in this layer.

2. Stratosphere: The stratosphere is the atmosphere from the top of the troposphere to an altitude of about 50 kilometers, the temperature in the layer usually increases with the increase of altitude, and the temperature at the bottom does not change much with the altitude.

3. Mesosphere: The mesosphere is the atmosphere from the top of the stratosphere to 85 kilometers, due to the low ozone content in the layer, and at the same time, the solar shortwave radiation that can be directly absorbed by nitrogen and oxygen has been mostly absorbed by the upper atmosphere, the vertical decline rate of temperature is very large, and the convective movement is strong.

4. Ionosphere: The ionosphere is an ionized region of the earth's atmosphere, and the entire earth's atmosphere above 60 kilometers is in a state of partial ionization or complete ionization. There are also people who refer to the entire ionized atmosphere as the ionosphere, so that the magnetosphere is considered to be part of the ionosphere.

5. The fugitive layer: The fugitive layer is the area where the atmosphere transitions to interstellar space, with no obvious boundary, extending to 1,000 kilometers from the earth's surface, where the temperature is very high, up to thousands of degrees, and the atmosphere is extremely thin, with a density of 1 billionth at sea level.

The atmosphere is composed of three parts: air, water vapor, and solid impurities suspended in the atmosphere. The atmosphere is the Earth's outermost gasosphere, encircling the oceans and land, and is about 1,000 kilometers thick, but there are no clear boundaries. The entire atmosphere exhibits different characteristics with different altitudes, and is divided into troposphere, stratosphere, ozone layer, mesosphere, thermosphere and fugitive layer, and above it is interstellar space.

The atmosphere, also known as the atmosphere, is a layer of mixed gas that surrounds the earth due to gravity, is the outermost gaseous layer of the earth, surrounding the ocean and land, the atmosphere has no exact upper bound, there are still thin gases and elementary particles at an altitude of 2000 16000 kilometers from the surface, there will also be a small amount of gas in the underground, soil and some rocks, they can also be considered as a component of the atmosphere, the main components of the earth's atmosphere are nitrogen, oxygen, argon, carbon dioxide and less than a proportion of trace gases, These gas mixtures are called air.

The troposphere is at the lowest level of the atmosphere, close to the Earth's surface, and is about 10,000 to 20,000 meters thick. The survival of animals and plants, and most of the activities of human beings, are also in this layer. Because the air convection in this layer is obvious, it is called the troposphere.

Above the stratosphere is the mesosphere, 50 to 85 km above the Earth's surface, where the air is already thin, and is characterized by a rapid decrease in air temperature with increasing altitude and strong vertical convection.

One of the main reasons why millions of things can survive on top of the earth is because of the thin atmosphere that surrounds our planet! So how exactly is our planet's atmosphere formed? The atmosphere of our planet is neither as dense as Venus nor as thin as Saturn!

How is the Earth's atmosphere formed? Everyone said that they should go. Generally speaking, it is believed that the evolution of the earth's atmosphere has roughly gone through three processes: the primitive atmosphere, the secondary atmosphere, and the present atmosphere.

Originally, during the formation of the Earth, it moved around the sun while absorbing dust and gases in its orbit. When the Earth's surface gradually condenses into a solid state, it is surrounded by a layer of atmosphere, which is the primordial atmosphere, and its main components are hydrogen and helium.

Because the earth's crust is still unstable and volcanic activity is frequent, the gases emitted by volcanoes form the Earth's secondary atmosphere. Its composition is mainly methane and hydrogen, with some ammonia and water vapor, but there is still no oxygen.

The formation of oxygen is the main indicator of the formation of the modern atmosphere, and its formation process is closely related to the emergence and development of life on Earth. The first life appeared in deep water that could not be reached by the sun's ultraviolet radiation, and then gradually moved to shallow water, and then developed into chloroplasts, and the photosynthesis of green plants became the most important cause of oxygen formation in the atmosphere.

The increase in oxygen forms the ,.. of the ozone layer at high altitudes

1. Primitive atmosphere: about 5 billion years ago, in the process of the formation of the earth, while moving around the sun, while absorbing the dust and gases in orbit, when the earth's surface gradually condensed into a solid state, surrounded by a layer of atmosphere, this is the primitive atmosphere, its main components are hydrogen and helium, almost no nitrogen, oxygen and carbon dioxide can be found, but due to the conversion of the earth's energy, the strong action of the solar wind and the small gravitational attraction of the earth when it was just formed, the primitive atmosphere quickly disappeared.

2. Secondary atmosphere: After the formation of the earth, due to the instability of the earth's crust and frequent volcanic activities, the volatile gases emitted during volcanic eruptions gradually replaced the original atmosphere and became the secondary atmosphere, the main components of which are carbon dioxide, methane, nitrogen, hydrogen sulfide and ammonia and other gases with heavy molecular weight.

3. Today's atmosphere: with the development of solar radiation to the depth of the earth's surface, oxygen is generated in the secondary atmosphere on the earth, and the emergence of oxygen provides an extremely favorable "hotbed" for the birth of life, so life is born on the earth, constantly evolving, the increase of oxygen forms an ozone layer at high altitude, and the photosynthesis of plants greatly increases the oxygen and carbon dioxide on the earth to form the current atmosphere, at this time, the atmosphere near the ground has obtained the current composition: nitrogen accounts for about 78%, oxygen accounts for about 21%, Argon is about 1%, and the sum of other trace gases is less than 1%.

There are different ways of dividing the structure of the Earth's atmosphere. But generally, it isIt is divided into five floors

The closest floor to the ground is:Troposphere。With an average thickness of about 12 km, the troposphere is the densest layer in the atmosphere, concentrating about 75% of the atmosphere and more than 90% of the water vapor mass. The most striking feature of the troposphere is that there are strong convective movements, and various weather phenomena occur within the troposphere.

Above the troposphere isStratosphere。The stratosphere is the atmosphere from the tropopause to an altitude of about 50 km, also known as the "stratosphere". Stratospheric airflow is mainly characterized by horizontal movement and weakened convective phenomena.

There is basically no moisture, it is clear and cloudless, and there are few weather changes, making it suitable for airplanes. At an altitude of 20 to 30 km, oxygen molecules are formed under the action of ultraviolet lightOzone layer, like a barrier to protect life on Earth from the sun's ultraviolet rays and energetic particles.

Above the stratosphere isMiddle layer,Also called "middle layer". It is the atmosphere from the top of the stratosphere to 85 km. The temperature near the mesopause is about 190K; The air is dominated by nitrogen and oxygen, and there is almost no ozone.

Air molecules can be ionized after absorbing the sun's ultraviolet radiation, which is customarily called the D layer of the ionosphere. In this layer, noctilucent clouds sometimes appear at dusk in summer at high latitudes.

And then above isIonosphere。It is the airspace of the Earth's upper atmosphere (partially overlapping with the mesosphere) that starts from about 50 kilometers above the ground and extends to an altitude of about 1,000 kilometers, in which atmospheric molecules are ionized under the sun's ultraviolet radiation, and there are quite a lot of free electrons and ions, which can change the propagation speed of radio waves, refract, reflect and scatter, produce the rotation of the polarization plane and be absorbed to varying degrees.

Above the mesosphere, to 500 kilometers above the Earth's surface, it is called ".Thermal layer”。From the mesosphere to the ionosphere, many interesting astronomical phenomena such as auroras, meteors, etc., often occur.

Further outward, there is the atmosphereOuter layer, also known as the escape layer or escape layer, is the outer atmosphere above the thermosphere, extending to 1,000 kilometers above the earth's surface. The atmosphere here is extremely thin, with a density of 1 billionth at sea level. The outer atmosphere is the outermost layer of the atmosphere, the area where the atmosphere transitions to interstellar space, and there is no obvious boundary between the outer atmosphere and space.

The height of the atmosphere is usually regarded as within 1,000 km, i.e., within the ionosphere, that is, the thickness of the atmosphere is about 1,000 km.