ionosphere

American  

[ahy-on-uh-sfeer] / aɪˈɒn əˌsfɪər /

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 British  

/ 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 Scientific  

/ 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 E region F region

---

ionosphere Cultural  

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

---

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

Derived Forms

• ionospheric
  adjective

Etymology

Origin of ionosphere

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

Example Sentences

By 1974, Dad was in charge of Cornell’s National Astronomy and Ionosphere Centerl, which managed the telescope—a position he held for more than a decade.

From National Geographic • Jan. 11, 2021

The Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, or Marsis, was developed and built by the Italians for the Mars Express mission, which entered orbit around Mars in 2003.

From New York Times • Jul. 25, 2018

For the latest discovery, researchers in Italy analysed three years of data gathered by an instrument called the Mars Advanced Radar for Subsurface and Ionosphere Sounding, or Marsis, onboard the Mars Express probe.

From The Guardian • Jul. 25, 2018