[strat-uh-sfeer] 
| 1. | 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. |
| 2. | (formerly) all of the earth's atmosphere lying outside the troposphere. |
| 3. | any great height or degree, as the highest point of a graded scale. |
The region of the atmosphere of the Earth above the troposphere. The stratosphere begins at an altitude of seven to ten miles and extends to approximately thirty miles.
| stratosphere (strāt'ə-sfîr') Pronunciation Key
The region of the Earth's atmosphere extending from the tropopause to about 50 km (31 mi) above the Earth's surface. The stratosphere is characterized by the presence of ozone gas (in the ozone layer) and by temperatures which rise slightly with altitude, due to the absorption of ultraviolet radiation. See also exosphere, mesosphere, thermosphere, troposphere., See illustration at atmosphere. |
əˌsfɪər