How does the ozone layer protect us from radiation?

Answer 1

Ozone (O3) exists at two levels in the atmosphere (troposphere and stratosphere).

The stratosphere is where the ozone hole over the Antarctica was discovered in the mid 1980’s.

O3 is concentrated at the poles due to stratospheric winds even though most is created near the equator. Also, the level of ozone varies naturally with the highest levels in early autumn and lowest in spring.

Of course the reason the ozone hole is a concern is due to the amount of uv light that is getting through. The light reaching the earth from the sun looks like this

Uv-C 200-280 nm is filtered out by O2 mostly due to the following reactions

O2 + light (< 241 nm)  2 O

O2 + light (> 241 nm)  O2*  O2 + heat

*exited molecule or atom

These reactions are very successful at filtering out uv-c and none makes it to the earth’s surface. This light would be damaging to eyes, skin etc.

Uv-B 280-320 nm is filtered mostly by O3. The O3 is first produced by the O radical from the earlier reaction

O + O2  O3 + heat

O3 + light (< 320 nm)  O2* + O*

The O* can of course then go back and create more O3.

All this is summarised in the Chapman cycle

Uv-A 320 – 400 nm makes it to the earth’s surface unfiltered but is the least damaging of the uv light and hence the least dangerous.

Answer 2

the ozone layer is like a barrier for some harmfully uv-rays that are coming from the sun....

Answer 3

Prevents entry of harmful UV rays, Impermeable and reflects them back.

Answer 4

Who knows and who cares? I just trust God to run things and I just go with the flow. How much easier that is than to worry if your toenail will go to heaven or not?