— tropospheric /trop'euh sfer"ik, -sfear"-, troh'peuh-/ , adj.
/trop"euh sfear', troh"peuh-/ , n. Meteorol.
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.
[ 1905-10; TROPO- + SPHERE ]