The ozone layer is the part of the Earth's atmosphere which contains relatively high concentrations of ozone (O3).
"Relatively high" means a few parts per million - much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere.
Although the concentration of ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation from the Sun.
The "thickness" of the ozone layer - that is, the total amount of ozone in a column overhead - varies by a large factor worldwide, being in general smaller near the equator and larger as one moves towards the poles.
It also varies with season, being in general thicker during the spring and thinner during the autumn.
Tropospheric ozone Ozone (O3) is a key constituent of the troposphere. Photochemical and chemical reactions involving it drive many of the chemical processes that occur ... >
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Nitrogen oxide NOx is a generic term for the various nitrogen oxides produced during combustion. They are believed to aggravate asthmatic conditions, react with the ... >
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Ozone Ozone (O3) is an allotrope of oxygen, the molecule consisting of three oxygen atoms instead of the more stable diatomic O2. Ozone is a powerful ... >
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Earth's atmosphere Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly 78% nitrogen and 21% ... >
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Oxygen Oxygen is a chemical element in the periodic table. It has the symbol O and atomic number 8. The element is the most common on Earth, composing ... >
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Autocatalysis A single chemical reaction is said to have undergone autocatalysis, or be autocatalytic, if the reaction product is itself the catalyst for that ... >
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