Why Does O₂ & O₃ Stay in the Stratosphere?

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In summary, the stratosphere contains both ozone (O₃) and oxygen (O₂) molecules, which are relatively heavy. However, they are able to remain in the upper atmosphere (>10km) due to the mixing caused by uneven heating from the sun and the creation of ozone at high altitudes. Ozone is not rising from the surface, as the ozone layer is largely created and destroyed in the upper atmosphere. Ozone at lower altitudes is considered a pollutant and is created through reactions with atmospheric oxygen and emissions from industrial processes. The weight of O₂ and O₃ is not a significant factor in their distribution in the stratosphere.
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Suraj M

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we all know that the stratosphere has ozone O₃ molecules and also O₂.:.but
O₂ and O₃ are heavy molecules (comparitively) why are they all the way up there(>10km) shouldn't they come down?
My guess ... because of that altitude maybe the centrifugal force acting on the molecules is enough to keep them up there..but then again Earth's rotation and there mass is a bit too small for a large enough centrifugal force
is there some other reason??
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Perhaps you would see such stratification if the atmosphere remained completely static. However, since the Earth rotates and is exposed to the sun, the atmosphere is heated unevenly, which causes a certain amount of mixing to occur by the winds which develop as a result.

Also, ozone is created at altitude by the effect which solar radiation has on the oxygen molecules present in the upper atmosphere; the ozone layer which protects the surface against UV radiation largely is created and destroyed by processes which occur at high altitudes, so the ozone molecules there are not rising from the surface. What ozone is present at low altitudes is regarded as a pollutant, and is created as a result of sunlight causing reactions of atmospheric oxygen with hydrocarbons and oxides of nitrogen emitted by combustion or other industrial processes.

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Suraj M said:
My guess ... because of that altitude maybe the centrifugal force acting on the molecules is enough to keep them up there..
Definitely not.

As SK points out,
1] there is plenty of mixing.
2] O3 is formed in the upper atmo.

That and the fact that O2's molar mass (31) is very similar to N2's (28). It's just not that heavy, comparatively.

1. Why does O₂ & O₃ stay in the stratosphere?

The stratosphere is characterized by strong winds and temperature inversion, which means that the temperature increases with altitude. This creates a stable environment where O₂ and O₃ molecules can remain in the stratosphere without being easily mixed with other gases in the lower atmosphere.

2. How do O₂ and O₃ molecules avoid being broken down in the stratosphere?

The stratosphere has a layer of ozone (O₃) that absorbs most of the UV radiation from the sun. This UV radiation is responsible for breaking down O₂ and O₃ molecules. Therefore, the presence of ozone in the stratosphere allows O₂ and O₃ to remain stable and not be broken down.

3. What is the role of gravity in keeping O₂ and O₃ in the stratosphere?

The force of gravity is responsible for keeping gases in the Earth's atmosphere, including O₂ and O₃, from escaping into space. In the stratosphere, the force of gravity is strong enough to hold O₂ and O₃ molecules in place, preventing them from rising to higher altitudes or escaping into space.

4. Can O₂ and O₃ molecules move between the stratosphere and other layers of the atmosphere?

O₂ and O₃ molecules can move between different layers of the atmosphere, but it is not easy for them to do so. The strong winds and temperature inversion in the stratosphere make it difficult for molecules to move in and out of this layer. Additionally, the presence of the ozone layer acts as a barrier, preventing easy movement of O₂ and O₃ molecules.

5. What would happen if O₂ and O₃ were not present in the stratosphere?

If O₂ and O₃ were not present in the stratosphere, the Earth's surface would be exposed to harmful levels of UV radiation from the sun. This would have detrimental effects on all living organisms, including humans. Ozone depletion, which leads to a decrease in O₃ molecules, has already shown negative effects on ecosystems and human health, highlighting the importance of these molecules in the stratosphere.

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