Which type of wave is likely to reflect back to earth due to the ionosphere interface?

The type of wave that is likely to reflect back to Earth due to the ionosphere interface is the sky wave. Sky waves are radio waves that are transmitted at an angle into the atmosphere and can propagate by being reflected from the ionosphere, which is a layer of the Earth's atmosphere that is ionized by solar and cosmic radiation. This reflection allows signals to travel over the horizon, making them suitable for long-distance communication.

The ionosphere acts as a mirror for certain frequencies, particularly high-frequency (HF) signals, allowing them to bounce back to Earth instead of escaping into space. This feature is crucial in amateur radio, some broadcasting, and certain aviation communications.

Other types of waves, such as ground waves, travel along the surface of the Earth and do not rely on reflection from the ionosphere, while space waves primarily propagate directly between transmitter and receiver without any significant interaction with the ionosphere. Surface waves also follow the contour of the Earth and do not depend on changes in atmospheric layers for their propagation.