" troposphere "

[Noun]  | "tro*po*sphere" | \ ˈtrō-pə-ˌsfir \

1: the lowest densest part of the earth's atmosphere in which most weather changes occur and temperature generally decreases rapidly with altitude and which extends from the earth's surface to the bottom of the stratosphere at about 7 miles (11 kilometers) high

Origin: 1908 ;

 Borrowed from French troposphère, from tropo- {see: |tropo-|tropo-} (in sense "change," as the troposphere is where weather changes take place) + -sphère {see: |-sphere|-sphere};

  * Note : The term was introduced, along with stratosphère {stratosphere|stratosphere}, by the French meteorologist Léon Tesserenc de Bort (1855-1913). Tesserenc de Bort apparently first used them in a paper read to a German meteorological society in Hamburg on September 30, 1908 ("La division de l'atmosphère en troposphère et stratosphère d'après les résultats de l'exploration de la haute atmosphère"). The paper was not subsequently published but is briefly summarized by C. Kassner in "Bericht über die elfte allgemeine Versammlung und Feier des 25-jährigen Bestehens der Deutschen Meteorologischen Gesellschaft zu Hamburg am 28. bis 30. September 1908," Meteorologische Zeitschrift, Band 26, Heft 1 (Januar, 1909), p. 6.;