Yang Song-qin

Yang Song-qin

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the atmosphere is a mixture of gases that forms a layer from 1000km to 1400 km around Earth. Most of the atmosphere is held close to Earth by the force of gravity, so the atmosphere gets thinner with increasing distance from Earth.

◆ atmosphere

can be divided into four distinct layers according to the vertical distance from the earth.

tropos phere

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The layer of air immediately adjacent to Earth's surface is called the troposphere. The troposphere, ranging in depth from 16 km over the equator to about 8 km over the poles, contains about 75 percent of the total mass of the atmosphere .This is where most weather events occur.

troposp here ◆

In this layer, there are all kinds of natural phenomena, such as wind, cloud, snow, thunder and lighting.

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The airflow has two action forms here: vertical and horizontal .

tropos phere ◆

Here also has a phenomenon of air temperature progressively decreasing. That

with the height going up, the

temperature decreases gradually (by degree). ◆

More commonly, air decrease 6.5℃ with the altitude of 1 km increasing.

tropos phere ◆

When air temperature progressively decreases, the air produces the action of convection from above and blow. In this time, the air is unstable, and is beneficial for diffusing of air pollutants.

tropos phere ◆

If the phenomena that with increasing of height, the air isn’t decrease but increase, In this time the air isn’t beneficial for diffusing of air pollutants. The temperature inversion will happen.

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stratos phere

The layer of air immediately above the troposphere is the stratosphere. It extends upward for about 50 km. Air temperature in the stratosphere is relatively constant, or may even increase slightly with increase in elevation.

stratosph ere ◆

This zone is of greatest importance to our environmental quality because it contains the ozone layer, which protects life on Earth by absorbing ultraviolet radiation from the sun. The ozone concentration in the stratosphere is about 1000 times greater than in the troposphere.

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Above the stratosphere are the mesosphere and the thermosphere. There is little interchange of materials between the troposphere, where human activity has an impact, and these two zones, so they won't be discussed further here.

Other action of the air

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As Earth absorbs heat from the sun, it transfers some of this heat to the air above it. The heated air expands and rises. When its heat content is radiated into space, the air-cools, becomes more dense, and settles back toward Earth.

westerlies

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According other scientists, The thickness of the ambient air is about 400 km. cosmic space over 1400km, air is very rarefaction. air can be divided into three layers from the earth, that is troposphere, stratosphere, and ionosphere.