Ozone layer

The ozone layer is a layer of Earth's atmosphere that has relatively high levels of ozone gas. This layer is mainly located in the lower part of the stratosphere, which is more than 20-30 km above the surface. The thickness of this layer is more in place and in season. [1]

O2 + ℎνuv → 2O
O + O2 ↔ O3
About 90 percent of the ozone in the atmosphere is included in the stratosphere. Ozone concentrations are about 20 and 40 kilometers (66,000 and 131,000 feet), where they are the best among the ranges from about 2 to 8 parts per million. If all parts of this ozone are compressed by the air pressure of the sea level, it will be only 3 millimeters (1/8 inch) thick!