Columbia Encyclopedia

Search results

212 results found

ozone layer

(Encyclopedia)ozone layer or ozonosphere, region of the stratosphere containing relatively high concentrations of ozone, located at altitudes of 12–30 mi (19–48 km) above the earth's surface. Ozone in the ozone...

ozone

(Encyclopedia)ozone ōˈzōn [key], an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a dens...

stratosphere

(Encyclopedia)stratosphere strătˈəsfēr [key], second lowest layer of the earth's atmosphere. The level from which it extends outward varies with latitude; it begins c.51⁄2 mi (9 km) above the poles, c.6 or 7 ...

Montreal Protocol

(Encyclopedia)Montreal Protocol, officially the Protocol on Substances That Deplete the Ozone Layer, treaty signed on Sept. 16, 1987, at Montreal by 25 nations; 197 nations are now parties to the accord. The protoc...

ozonosphere

(Encyclopedia)ozonosphere: see ozone layer.

Crutzen, Paul Jozef

(Encyclopedia)Crutzen, Paul Jozef, 1933–2021, Dutch atmospheric chemist, grad. Univ. of Stockholm (Ph.D. 1968, D.Sc. 1973). After working (1977–80) for the Nation...

Rowland, Frank Sherwood

(Encyclopedia)Rowland, Frank Sherwood, 1927–2012, American chemist, b. Delaware, Ohio, Ph.D. Univ. of Chicago, 1952. Rowland taught at Princeton from 1952 to 1956 and at the Univ. of Kansas from 1956 to 1964, whe...

atmosphere

(Encyclopedia)CE5 Atmosphere atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other plane...

Molina, Mario

(Encyclopedia)Molina, Mario (Mario José Molina-Pasquel y Henríquez), 1943–2020, Mexican chemist, Ph.D. Univ. of California, Berkeley, 1972. Molina was a professor at the Univ. of California, Irvine from 1975 to...

chlorofluorocarbons

(Encyclopedia)chlorofluorocarbons klōrˌəflo͝orˈəkärˌbənz, klôrˌ– [key] (CFCs), organic compounds that contain carbon, chlorine, and fluorine atoms. CFCs are highly effective refrigerants that were deve...