A region in the atmosphere above 50 kilometers from the surface where relatively large concentrations of ions and free electrons exist. The ionosphere is important for human communications because it [..]

A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface. It is located between the mesosphere and the exosphere and is i [..]

region of the outer atmosphere, 1926, from ion + sphere. Coined by Scottish radar pioneer Robert A. Watson-Watt (1892-1973). So called because it contains many ions.

A region of charged particles in a planet's upper atmosphere. In Earth's atmosphere, the ionosphere begins at an altitude of about 25 miles and extends outward about 250.

An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist.

outer layer of the Earth's atmosphere, 80-400 kilometers (50-250 miles) above the surface.

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 i [..]

A region of the Earth’s upper atmosphere where solar radiation ionizes the air molecules. This region affects the transmission of radio wave and extends from 50 to 400 kilometers (30 to 250 miles) abo [..]

A region of the earth's atmosphere where ionization caused by incoming solar radiation affects the transmission of GPS radio waves. It extends from a height of 50 kilometers (30 miles) to 400 kil [..]

A region of the Earth’s upper atmosphere where solar radiation ionizes the air molecules. This region affects the transmission of radio waves and extends from 50 to 400 kilometers (30 to 250 miles) ab [..]

That part of the atmosphere, extending from about 70 to 500 kilometers, in which ions and free electrons exist in sufficient quantities to reflect and/or refract electromagnetic waves. [After JP1]  

The region of the atmosphere between about 70 km (43 mi) and several hundred kilometers in altitude. It is characterized by a high concentration of ions.

layer of electrically charged particles in the thermosphere. island -

Several layers of ionized air high in the atmosphere. The ionosphere plays an important part in reflecting radio waves.

(n) the outer region of the Earth's atmosphere; contains a high concentration of free electrons

Is the part of the atmosphere that is ionized by solar radiation, and too tenuous to be cooled by contact with other air. It forms the inner edge of the magnetosphere and has practical importance because it reflects radio waves to distant places on Earth.

(n.) The zone of the earth's upper atmosphere, between 80- and 500-km altitude, where charged subatomic particles (chiefly protons and electrons) are trapped by the earth's magnetic field. ~ [..]

Layer of the upper atmosphere where electron and ionization activity is particularly high. Electromagnetic waves are subjected to a number of perturbing effects as they pass through the ionosphere.  

Layer of the upper atmosphere where electron and ionisation activity is particularly high.Electromagnetic waves are subjected to a number of perturbing effects as they pass through the ionosphere

The part of the earth's atmosphere beginning at an altitude of about 30 miles and extending outward 300 miles or more. The ionosphere contains a large quantity of positively and negatively charge [..]

The part of the atmosphere, between the mesosphere and exosphere. Sufficient quantities of ions and free electrons exist to reflect and/or refract electromagnetic waves.

The band of charged particles 80 to 120 miles above the earth's surface, which represent a nonhomogeneous and dispersive medium for radio signals.  

A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface. It is located between the mesosphere and the exosphere and is included as part of the thermosphere.

An atmospheric layer with a high concentration of ions and free electrons.

An atmospheric layer dominated by charged, or ionized, atoms that extends from about 38 to 400 miles above the Earth's surface.

The region of the Earth’s upper atmosphere containing free electrons and ions produced by ionization of the constituents of the atmosphere by solar ultraviolet radiation at short wavelengths < 100nm) and energetic precipitating particles. The ionosphere influences radiowave propagation of frequencies less than about 300 MHz. (See D region, E reg [..]

A region of the Earth’s upper atmosphere where solar radiation ionizes the air molecules. This region affects the transmission of radio wave and extends from 50 to 400 kilometers (30 to 250 miles) above the Earth's surface.

The region of the upper atmosphere from 80 to 900 km (50 to 600 mi) that contains a relatively high concentration of ions (electrically charged particles).

Also known as the thermosphere. A layer in the atmosphere

That part of the atmosphere, extending from about 70 to 500 kilometers, in which ions and free electrons exist in sufficient quantities to reflect and/or refract electromagnetic waves.

A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface. It is located between the mesosphere and the exosphere and is included as part of the thermosphere.

A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface. It is located between the mesosphere and the exosphere and is i [..]

A complex atmospheric

Gas consisting of charged particles (ions and electrons) that mingle with the thermosphere to form the atmosphere of high altitudes.

A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface. It is located between the mesosphere and the exosphere and is i [..]

A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth’s surface. It is located between the mesosphere and the exosphere and is included as part of the thermosphere.

The most important region of the atmosphere extending from 31 miles to 250 miles above sea level. Contains four cloud-like layers that affect radio waves.

The part of the Earth's atmosphere beginning at an altitude of about 50 kilometers (31 miles) and extending outward 500 kilometers (310 miles) or more. The similar region of the atmosphere of anot [..]