ionosphere
Americannoun
noun
-
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.
Discover More
In 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.
Other Word Forms
- ionospheric adjective
Etymology
Origin of ionosphere
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
As the storm weakened, the plasmasphere began to replenish with particles supplied by the ionosphere.
From Science Daily
The satellites will map the magnetic fields, upper atmosphere and ionosphere of Mars in 3D, gathering data that will help humans land or even settle on the Red Planet.
From MarketWatch
The vortex spins fastest in the ionosphere, progressively weakening as it reaches each deeper layer.
From Science Daily
The storms can also disrupt GPS signals by forcing those satellites to transmit through a more electron-rich ionosphere, a layer of the upper atmosphere.
From Science Magazine
This creates regions on Jupiter where the solar wind, which carries some of the sun's magnetic field lines, directly interacts with the planet's ionosphere and atmosphere.
From Science Daily
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.