Ozone layer
From Wikipedia, the free encyclopedia
The ozone layer is a layer of ozone high up in the Earth's atmosphere (stratosphere). In the regionm between about 10 kliometres and about 50 kilometres above ground, the atmosphere contains more ozone (O3). The exact amount of ozone that can be found varies, the seasons influence it; it is also different in different places on the earth. [1] This layer can absorb between 93 and 99 percent of the ultraviolet radiation from the sun.[2] This radiation is dangerous to many living organisms on earth.
Over the last hundred years the ozone layer has been damaged by man-made chemicals, especially ones called CFCs (chlorofluorocarbons). CFCs were used in spray cans, but also as solvents or as cooling agents in refrigerators. They have been replaced by other substances for most applications. There is now a hole in the layer over Antarctica. This means that there will be more ozone in the atmosphere, and that diseases of the skin which are related to this UV radiation will be more common.
The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson. Its properties were explored in detail by the British meteorologist G. M. B. Dobson, who developed a simple spectrophotometer, the Dobsonmeter. This tool could be used to measure the ozone levels found in the stratosphere from the ground. Between 1928 and 1958 Dobson established a worldwide network of ozone monitoring stations. Most of these stations are still in use today. The "Dobson unit", a convenient measure of the total amount of ozone in a column overhead, is named in his honor.
[change] References
- ↑ Science: Ozone Basics.. Retrieved on 29 January 2007.
- ↑ Ozone layer. Retrieved on 23 September 2007.