ion·​o·​sphere | \ ī-ˈä-nə-ˌsfir How to pronounce ionosphere (audio) \

Definition of ionosphere

: the part of the earth's atmosphere in which ionization of atmospheric gases affects the propagation of radio waves, which extends from about 30 miles (50 kilometers) to the exosphere, and which is contiguous with the upper portion of the mesosphere and the thermosphere also : a comparable region of charged particles surrounding another celestial body (such as Venus)

Keep scrolling for more

Other Words from ionosphere

ionospheric \ ˌī-​ˌä-​nə-​ˈsfir-​ik How to pronounce ionosphere (audio) , -​ˈsfer-​ \ adjective
ionospherically \ ˌī-​ˌä-​nə-​ˈsfir-​i-​k(ə-​)lē How to pronounce ionosphere (audio) , -​ˈsfer-​ \ adverb

Examples of ionosphere in a Sentence

Recent Examples on the Web Solar weather can heat up molecules in the ionosphere, causing this atmospheric layer to expand and, in some cases, contract. Jennifer Leman, Popular Mechanics, 27 May 2021 What inspired the idea that JJ was actually this spirit that was in the ionosphere? Chancellor Agard,, 25 May 2021 The signal must have been created as the Parker probe cruised through the ionosphere of Venus. Mike Wehner, BGR, 5 May 2021 The Venusian ionosphere leaks energized gas into space, which suggests its atmosphere has changed over time. Ashley Strickland, CNN, 4 May 2021 Scientists with the European Space Agency have discovered that a part of the upper atmosphere of Venus — its ionosphere — acts surprisingly different depending on daily changes in the sun's weather. Miriam Kramer, Scientific American, 31 Jan. 2013 That's the question Black Lightning left us with last week after Gambi (James Remar) reconstituted Jennifer's physical body, which exploded in the ionosphere. Chancellor Agard,, 16 Mar. 2021 The space hurricane spotted by the research team in Earth’s ionosphere was spinning in a counterclockwise direction. Doyle Rice, USA TODAY, 2 Mar. 2021 The discovery was made using ESA's Venus Express spacecraft, which observed Venus's ionosphere during a period of low solar wind in 2010 to see exactly how the sun affects the way the planet's atmosphere functions. Miriam Kramer, Scientific American, 31 Jan. 2013

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ionosphere.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of ionosphere

1926, in the meaning defined above

History and Etymology for ionosphere

ion or ion(ization) + -o- + -sphere

Note: The term was introduced by the British engineer and physicist Robert A. Watson-Watt (1892-1973), apparently first in an unpublished letter (November 8, 1926) to the secretary of the Radio Research Board, a government agency (see Nature, vol. 224, December 13, 1969, p. 1096). Watson-Watt used it in print in the Quarterly Journal of the Royal Meteorological Society, vol. 55 (1929), p. 278.

Keep scrolling for more

Learn More about ionosphere

Time Traveler for ionosphere

Time Traveler

The first known use of ionosphere was in 1926

See more words from the same year

Statistics for ionosphere

Last Updated

31 May 2021

Cite this Entry

“Ionosphere.” Dictionary, Merriam-Webster, Accessed 12 Jun. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

More Definitions for ionosphere


ion·​o·​sphere | \ ī-ˈä-nə-ˌsfir How to pronounce ionosphere (audio) \

Kids Definition of ionosphere

: the part of the earth's atmosphere beginning at an altitude of about 30 miles (50 kilometers) and extending outward that contains electrically charged particles

More from Merriam-Webster on ionosphere

Nglish: Translation of ionosphere for Spanish Speakers Encyclopedia article about ionosphere


Test Your Vocabulary

Name that Thing: Dog Breeds

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!