| A | B |
|---|
| Atmosphere | the gaseous envelope surrounding the earth; the air |
| Ozone | an unstable, poisonous allotrope of oxygen, O3, which is formed naturally in the ozone layer from atmospheric oxygen by electric discharge or exposure to ultraviolet radiation, also produced in the lower atmosphere by the photochemical reaction of certain pollutants. It is a highly reactive oxidizing agent used to deodorize air, purify water, and treat industrial wastes |
| Atmospheric pressure | the pressure exerted by the earth's atmosphere at any given point |
| Troposphere | the lowest layer of the atmosphere, 6 mi. (10 km) high in some areas and as much as 12 mi. (20 km) high in others, within which there is a steady drop in temperature with increasing altitude and within which nearly all cloud formations occur and weather conditions manifest themselves |
| Stratosphere | the region of the upper atmosphere extending upward from the tropopause to about 30 miles (50 km) above the earth, characterized by little vertical change in temperature |
| Mesosphere | the region between the ionosphere and the exosphere, extending from about 250–650 mi. above the surface of the earth; the region between the stratosphere and the thermosphere, extending from about 20–50 mi. above the surface of the earth |
| Thermosphere | the region of the upper atmosphere in which temperature increases continuously with altitude, encompassing essentially all of the atmosphere above the mesosphere |
| Electromagnetic spectrum | the entire spectrum, considered as a continuum, of all kinds of electric, magnetic, and visible radiation, from gamma rays having a wavelength of 0.001 angstrom to long waves having a wavelength of more than 1 million km. |
| Greenhouse effect | an atmospheric heating phenomenon, caused by short-wave solar radiation being readily transmitted inward through the earth's atmosphere but longer-wavelength heat radiation less readily transmitted outward, owing to its absorption by atmospheric carbon dioxide, water vapor, methane, and other gases; thus, the rising level of carbon dioxide is viewed with concern |
| Conduction | the transfer of heat between two parts of a stationary system, caused by a temperature difference between the parts |
| Convection | the transfer of heat by the circulation or movement of the heated parts of a liquid or gas |
| Coriolis effect | the apparent deflection (Coriolis acceleration) of a body in motion with respect to the earth, as seen by an observer on the earth, attributed to a fictitious force (Coriolis force) but actually caused by the rotation of the earth and appearing as a deflection to the right in the Northern Hemisphere and a deflection to the left in the Southern Hemisphere |
| Trade winds | any of the nearly constant easterly winds that dominate most of the tropics and subtropics throughout the world, blowing mainly from the northeast in the Northern Hemisphere, and from the southeast in the Southern Hemisphere |
| Jet stream | strong, generally westerly winds concentrated in a relatively narrow and shallow stream in the upper troposphere of the earth |
