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[trop-uh-sfeer, troh-puh-] /ˈtrɒp əˌsfɪər, ˈtroʊ pə-/
noun, Meteorology
the lowest layer of the atmosphere, 6 miles (10 km) high in some areas and as much as 12 miles (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
Related forms
[trop-uh-sfer-ik, -sfeer-, troh-puh-] /ˌtrɒp əˈsfɛr ɪk, -ˈsfɪər-, ˌtroʊ pə-/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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British Dictionary definitions for tropospheric


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
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Word Origin and History for tropospheric



1914, from French troposphère, literally "sphere of change," coined by French meteorologist Philippe Teisserenc de Bort (1855-1913) from Greek tropos "a turn, change" (see trope) + sphaira "sphere" (see sphere).

Online Etymology Dictionary, © 2010 Douglas Harper
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tropospheric in Science
  (trō'pə-sfîr', trŏp'ə-)   
The lowest and densest region of the Earth's atmosphere, extending from the Earth's surface to the tropopause. The troposphere is characterized by temperatures that decrease with increasing altitude. At the top of this region, temperatures are close to -55°C (-67°F). The weather, major wind systems, and cloud formations occur mostly in the troposphere. See also exosphere, mesosphere, stratosphere, thermosphere., See illustration at atmosphere.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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tropospheric in Culture
troposphere [(troh-puh-sfeer, trop-uh-sfeer)]

The lowest layer of the atmosphere of the Earth, extending from ground level to an altitude of seven to ten miles.

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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