ionosphere
the region of the earth's atmosphere between the stratosphere and the exosphere, consisting of several ionized layers and extending from about 50 to 250 miles (80 to 400 km) above the surface of the earth.
Origin of ionosphere
1Other words from ionosphere
- i·on·o·spher·ic [ahy-on-uh-sfer-ik], /aɪˌɒn əˈsfɛr ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
British Dictionary definitions for ionosphere
/ (aɪˈɒnəˌsfɪə) /
Derived forms of ionosphere
- ionospheric (aɪˌɒnəˈsfɛrɪk), adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for ionosphere
[ ī-ŏn′ə-sfîr′ ]
A region of the Earth's upper atmosphere, extending from a height of 70 km (43 mi) to 400 km (248 mi) and containing atoms that have been ionized by radiation from the Sun. The ionosphere lies mostly in the lower thermosphere and is subdivided into three regions, the D region (70 km to 90 km; 43 to 56 mi), the E region (90 km to 150 km; 56 to 93 mi), and the F region (150 km to 400 km; 93 to 248 mi). The concentration of ionized atoms is lowest in the D region, intermediate in the E region, and highest in the F region. The ionosphere is useful for radio transmission because radio waves, which normally propagate in straight lines, are reflected off the ionized gas particles, thereby being transmitted long distances across the Earth's curved surface. See more at D region E region F region.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for ionosphere
[ (eye-on-uh-sfeer) ]
A region of the atmosphere that begins at an altitude of about thirty miles.
Notes for ionosphere
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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