If a gas expands equally in all directions, then how does the ozone layer stay where it is?

Question

I have researched this question, and all that my sources tell me is that that area has the perfect conditions to create ozone. But, once the ozone is made, it seems that it would expand and disperse itself throughout the atmosphere rather then remain in such a small area.

Answer 1

Ozone will slowly diffuse down because it is heavy and will be destroyed in collisions when it encounters "pollutants". Expansion is not quite the right way to look at it because that implies moving into a lower pressure region. In the mixing of gasses in pressure equilibrium the movement of a molecule (diffusion) is hindered by collisions so for large distances can take a long time. So the reason that there is a layer is that is where it is created. If the creation stopped the ozone layer would disappear
"Ozone (O3) is generated when an oxygen molecule (O2) is dissociated to an oxygen atom (O) by ultraviolet light and the oxygen atom combines with an oxygen molecule (O2).
The dense ozone layer is formed at 20 - 30 kilometers above the ground. The number of oxygen molecules, which are an ingredient of ozone, decreases with increasing altitude, but the intensity of ultraviolet light, which breaks down the oxygen molecules, increases as altitude increases. According to these two factors, ozone generation becomes highest at around 20 - 30 kilometers."

Answer 2

This is more of a guess. Ozone easily breaks down into oxygen on contact with a free oxygen atom, producing two molecules of oxygen (O3 + O = 2O2). It it got any lower, I assume it would come into contact with free oxygen atoms and become molecules of oxygen. This occurs in the upper atmosphere, where it is regenerated by ultraviolet light breaking apart oxygen molecules into individual atoms which are then untied with an unbroken oxygen molecule to create a new molecule of ozone. Since the ozone itself keeps the ultraviolet from going all the way to the ground, this process does not occur further down in the atmosphere. Since the process only occurs there, I assume that it is also restricted to the area.

Try the following article at Wikipedia for more (and its various links):

Answer 3

Ozone, my fine feathered friend, is 03, or a trioxyde molecule, created by lightening and such. It is created high in the atmosphere by the arc of lightening and other processes. but since it is heavier than nitrogen, slowly sinks. Now, to top that off, the hydrocarbons released by certain aerosol sprays are actually lighter than 03, interact and displace it breaking it down to a simpler molecule, 02 for example. I am not sure about your comment that it remains in such a small area. You may need to recheck that.

Answer 4

The main process of ozone production in the upper atmospher is ultraviolet readiaton from the sun splitting O2 molecules into single oxygen atoms which then bind with other O2 molecules forming O3