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Ozone is lost by reaction with atomic oxygen (plus other trace atoms). The ozone–oxygen cycle is the process by which ozone is continually regenerated in Earth's stratosphere, converting ultraviolet radiation (UV) into heat. In 1930 Sydney Chapman resolved the chemistry involved. The process is commonly called the Chapman cycle by atmospheric ...
Chapman is credited with working out, in 1930, the photochemical mechanisms that give rise to the ozone layer. [11] Chapman is recognised as one of the pioneers of solar-terrestrial physics. [4] This interest stemmed from his early work on the kinetic theory of gases. Chapman studied magnetic storms and aurorae, developing theories to explain ...
Essentially all UVC (100–280 nm) is blocked by dioxygen (at 100–200 nm) or by ozone (at 200–280 nm) in the atmosphere. The shorter portion of this band and even more energetic UV causes the formation of the ozone layer, when single oxygen atoms produced by UV photolysis of dioxygen (below 240 nm) react with more dioxygen. The ozone layer ...
The Earth's ozone layer formed about 500 million years ago, when the neoproterozoic oxygenation event brought the fraction of oxygen in the atmosphere to about 20%. [7] The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in 1930.
A gamma ray burst would deplete the ozone layer, allowing UV radiation through. The mechanism describing the formation of the ozone layer was described by British mathematician and geophysicist Sydney Chapman in 1930, and is known as the Chapman cycle or ozone–oxygen cycle. [8]
Ozone in the troposhere is determined by photochemical production and destruction, dry deposition and cross-tropopause transport of ozone from the stratosphere. [2] In the Arctic troposphere, transport and photochemical reactions involving nitrogen oxides and volatile organic compounds (VOCs) as a result of human emissions also produce ozone resulting in a background mixing ratio of 30 to 50 ...
Stage 3 (1.85–0.85 Ga): O 2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer. Stages 4 and 5 (0.85 Ga–present): O 2 sinks filled, the gas accumulates.
The Chapman rearrangement is the thermal conversion of aryl N-arylbenzimidates to the corresponding amides, via intramolecular migration of an aryl group from oxygen to nitrogen. [4] It is named after Arthur William Chapman , who first described it, [ 5 ] and is conceptually similar to the Newman–Kwart rearrangement .