ionosphere
nounA region of the earth’s atmosphere where ionization caused by incoming solar radiation affects the transmission of radio waves. It extends from a height of 70 kilometers (43 miles) to 400 kilometers (250 miles) above the surface.
nounthe outer region of the earth’s atmosphere, beyond which is the
The part of the Earth’s
The similar region of the atmosphere of another planet.
nounthe outer region of the Earth’s atmosphere; contains a high concentration of free electrons