1. a region of Earth's atmosphere containing ionized gases that extends from about 50 to 1,000 kilometers above the surface and reflects radio waves.
Usage: scientific term; typically used in singular form

Examples

• The ionosphere plays a crucial role in long-distance radio communication.
• Solar radiation ionizes gases in the ionosphere, creating charged particles.
• Radio waves bounce off the ionosphere, allowing broadcasts to reach distant locations.
• The ionosphere's density varies with time of day and solar activity.
• Scientists study the ionosphere to understand atmospheric phenomena and space weather.