troposphere Meteorol.
(ˈtrɒpə-, ˈtrəʊpəʊsfɪə(r))
[f. tropo- + sphere n.]
The lowest region of the atmosphere, extending to a height of 8 to 18 km. and marked by convection and a general decrease of temperature with height.
| 1914 Q. Jrnl. R. Meteorol. Soc. XL. 108 M. Teisserenc de Bort discovered that the atmosphere is divided into two parts, the troposphere, which extends from the surface to about 7 miles, and the stratosphere, which lies above. 1922 Nature 2 Feb. 141/1 In the lower layer, called the troposphere, the atmospheric gases are kept well mixed up by winds and convection. 1951 [see exosphere s.v. exo-]. 1982 New Scientist 21 Jan. 151/1 Dust in the troposphere, the lowest layer of the atmosphere, is soon washed out by rain. |
Hence tropoˈspheric a., of, pertaining to, or involving the troposphere; tropospheric scatter = troposcatter.
| 1939 Proc. IRE XXVII. 634 It is believed that most of the tropospheric reflections occur at air-mass boundaries or other similar discontinuities. 1955 Ibid. XLIII. 1336 (heading) Some tropospheric scatter propagation measurements near the radio horizon. 1966 Electronics 17 Oct. 137 The system..is a wideband tropospheric scatter and microwave network consisting of 100 sites. It hops across the Mediterranean from the center of Spain to eastern Turkey, covering 6,000 miles and five nations. 1973 Guardian 18 May 18/5 With tropospheric fallout there is a steep rise in the level of iodine 131 in milk. |