the lowest atmospheric layer, about 18 kilometres (11 miles) thick at the equator to about 6 km (4 miles) at the Poles, in which air temperature decreases normally with height at about 6.5°C per km
Derived forms
tropospheric (ˌtrɒpəˈsfɛrɪk)
adjective
troposphere in American English
(ˈtroʊpəˌsfɪr; ˈtrɑpəˌsfɪr)
noun
the atmospheric zone or shell below the tropopause, characterized by water vapor, vertical winds, weather, and decreasing temperatures with increasing altitude