ionosphere

noun

ion·​o·​sphere ī-ˈä-nə-ˌsfir 

: 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

ˌī-ˌä-nə-ˈsfir-ik 

-ˈsfer-

adjective

ionospherically

ˌī-ˌä-nə-ˈsfir-i-k(ə-)lē 

-ˈsfer-

adverb

Examples of ionosphere in a Sentence

Recent Examples on the Web

The radiation caused a sudden disturbance to the Earth’s ionosphere, even though the source was an explosion nearly 2 billion light years away. —Chris Impey, Discover Magazine, 8 Apr. 2024

In reality, a solar eclipse brings a temporary sharp drop in solar radiation — an event that ham radio operators have been eagerly anticipating for months, with competitions and experiments looking to fill the Earth's suddenly radiation-free ionosphere with radio signals. —Bill Chappell, NPR, 8 Apr. 2024

During the 2023 annular eclipse, instruments on the rockets measured sharp, immediate changes in the ionosphere. —Ashley Strickland, CNN, 3 Apr. 2024

Scientists know the ionosphere evolves in a 24-hour process, from day to night, says Frissell. —Catherine Duncan, Smithsonian Magazine, 18 Mar. 2024

By measuring the strength of those signals information about the height, density and dynamics of the ionosphere can be collected. —Elizabeth Weise, USA TODAY, 31 Mar. 2024

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

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The term was introduced by the British engineer and physicist Robert A. Watson-Watt (1892-1973), apparently first in an unpublished letter (November 8, 1926) to the secretary of the Radio Research Board, a government agency (see Nature, vol. 224, December 13, 1969, p. 1096).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

Kids Definition

ionosphere

noun

ion·​o·​sphere ī-ˈän-ə-ˌsfi(ə)r 

: 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

ī-ˌän-ə-ˈsfi(ə)r-ik 

-ˈsfer-

adjective