单词 | ionosphere |
释义 | ionosphere[ ahy-on-uh-sfeer ] / aɪˈɒn əˌsfɪər / nounthe 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 ionosphereFirst recorded in 1925–30; iono- + -sphere OTHER WORDS FROM ionospherei·on·o·spher·ic [ahy-on-uh-sfer-ik], /aɪˌɒn əˈsfɛr ɪk/, adjectiveWords nearby ionosphereionone, ionopause, ionophore, ionophoresis, ionosonde, ionosphere, ionospheric wave, ionotropic receptor, ionotropy, ion propulsion, ion rocket Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 Example sentences from the Web for ionosphereBritish Dictionary definitions for ionosphereionosphere / (aɪˈɒnəˌsfɪə) / nouna region of the earth's atmosphere, extending from about 60 kilometres to 1000 km above the earth's surface, in which there is a high concentration of free electrons formed as a result of ionizing radiation entering the atmosphere from spaceSee also D region, E region, F region Derived forms of ionosphereionospheric (aɪˌɒnəˈsfɛrɪk), adjectiveCollins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cultural definitions for ionosphereionosphere [ (eye-on-uh-sfeer) ] A region of the atmosphere that begins at an altitude of about thirty miles. notes for ionosphereIn this region, free particles carrying an electrical charge, atoms ionized (see ionization) by radiation from the sun, reflect radio waves. “Bouncing” radio waves off the ionosphere makes communication possible over long distances of the surface of the Earth. 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. Scientific definitions for ionosphereionosphere [ 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. |
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