definition for troposphere for kids
The troposphere is the lowermost portion of Earth's atmosphere and the one in which most weather phenomena occur; this layer extends to an altitude of 7-17 km, depending on latitude. Generally, jets fly near the top of this layer. The troposphere is directly below the stratosphere. The word troposphere stems from the Greek tropos for turning or mixing. This region, constantly in motion, is the densest layer. Nitrogen and oxygen are the primary gases, within this region. The tropopause marks the limit of the troposphere and the beginning of the stratosphere. The temperature above the tropopause increases slowly with height up to about 50 km. In telecommunication, the term troposphere has the following meanings: 1. The lower layers of atmosphere, in which the change of temperature with height is relatively large.