How is ozone formed over the troposphere?
Above troposphere is the ozone layer. Here the ozone is formed by UV rays.
the ozone layer is actually in the stratosphere. when that layer gets depleted, the UV rays penetrate into the troposphere and eventually form ozone there. the ozone formed there is the tropospheric ozone. this ozone however has a short photochemical life in the troposphere and thus disintegrates too fast to consolidate its structure.
The ozone layer absorbs a large portion of incoming UV radiation, which keeps ground-level ozone from forming. A higher percentage of UV radiation entering the troposphere would allow a greater amount of ozone to form in the troposphere. Ozone is a pollutant in the troposphere. By regulating the amount of UV radiation that enters the troposphere, the ozone layer also regulates the amount of ozone formation in the troposphere.
Ozone is formed anywhere oxygen and ionizing radiation is present (ozone layer, commercial ozone generators). There are some additional chemical methods, involving lower energy light (ozone as a pollutant, troposphere), or essentially no light at all (antibody production in fighting infection, ozone is a decay product of that attack; also phosphorous reactions).
The name is typical political doublespeak. Same ozone, just two different areas containing it. Ozone is required above the lower troposphere (the ozone layer is in the lower stratosphere) to absorb UV-B from the Sun to protect all surface life. When ozone is formed in the troposphere (where we and our food supply live), its oxidative properties are such that it hurts / kills all life that comes in contact with it.