ionosphere

noun

ion·​o·​sphere ī-ˈä-nə-ˌsfir How to pronounce ionosphere (audio)
: 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)
ionospheric adjective
ionospherically adverb

Examples of ionosphere in a Sentence

Recent Examples on the Web The data will inform how the ionosphere behaves when the sun is blocked, in comparison to before and after the eclipse. Catherine Duncan, Smithsonian Magazine, 18 Mar. 2024 So when Jennifer dissipated in the ionosphere earlier in the season, JJ used it as an opportunity to get a corporeal body and take over her life. Chancellor Agard, EW.com, 25 May 2021 Usually, ham-radio operators can chat across distances of several thousand kilometers by bouncing radio waves off the ionosphere between receivers, but a total solar eclipse’s disruption of the ionosphere can change communication conditions. Jonathan O'Callaghan, Scientific American, 3 Jan. 2024 The ionosphere is one of the Earth’s atmospheric layers, stretching from 60 km to more than 950 km in altitude. Dhananjay Khadilkar, Ars Technica, 17 Nov. 2023 According to Piersanti, typically the ionosphere dynamics is completely driven by the Sun. Dhananjay Khadilkar, Ars Technica, 17 Nov. 2023 The goal is to see how eclipses set off atmospheric waves in the ionosphere nearly 200 miles (320 kilometers) up that could disrupt communications. Marcia Dunn, The Christian Science Monitor, 13 Oct. 2023 On Saturday, some researchers plan to use ham radios to study how solar eclipses affect the ionosphere, the part of Earth’s atmosphere that meets space. Zolan Kanno-Youngs, New York Times, 13 Oct. 2023 The space agency will also be broadcasting a live feed of three rocket launches that are part of its Atmospheric Perturbations around the Eclipse Path (APEP) mission to study how Earth’s ionosphere responds to a sudden drop in sunlight. John Kennedy, Popular Science, 12 Oct. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ionosphere.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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.

First Known Use

1926, in the meaning defined above

Time Traveler
The first known use of ionosphere was in 1926

Dictionary Entries Near ionosphere

Cite this Entry

“Ionosphere.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ionosphere. Accessed 28 Mar. 2024.

Kids Definition

ionosphere

noun
ion·​o·​sphere ī-ˈän-ə-ˌsfi(ə)r How to pronounce ionosphere (audio)
: the part of the earth's atmosphere beginning at an altitude of about 30 miles (50 kilometers) and extending outward that contains free electrically charged particles
ionospheric adjective

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