ionosphere

[ ahy-on-uh-sfeer ]

noun

1. the 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.

ionosphere

/ aɪˈɒnəˌsfɪə; aɪˌɒnəˈsfɛrɪk /

noun

1. a 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 space See also D region E region F region

ionosphere

/ ī-ŏn′ə-sfîr′ /

1. 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.
2. See more at D region

ionosphere

1. A region of the atmosphere that begins at an altitude of about thirty miles.

Notes

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 .

Derived Forms

• ionospheric, adjective

Other Words From

• i·on·o·spher·ic [ahy-on-, uh, -, sfer, -ik], adjective

Word History and Origins

Origin of ionosphere¹

First recorded in 1925–30; iono- + -sphere

Example Sentences

The ionosphere of Eisberg was much deeper and, although the intensity was less, the duration was much longer.

From Project Gutenberg

It was not the intensity of the ionosphere that cracked the drive of the Brainchild; it was the duration.

From Project Gutenberg

Extensive reports on the condition 176 of the ionosphere poured into headquarters.

From Project Gutenberg

Without the landing grid and the power it took from the ionosphere, they could not receive supplies from the rest of the universe.

From Project Gutenberg

Then we were able to modify that to heave sand and to let it tap the ionosphere.

From Project Gutenberg