By acting as a reflector.
The ionosphere has nothing to do with radioactivity, and there is nothing in nature that is called a "radio active wave."Because the ionosphere contains electrical charges, it is able to reflect radio waves.
Any Amplitude Modulated radio signal will penetrate the ionosphere if its carrier frequency is high enough. Signals in the commercial AM broadcast band, with frequencies between 530 and 1700 KHz, aren't high enough. Most of their energy reflects from the ionosphere.
electromagnetic waves do not require medium for their propagation. such as radio waves.
You can hear AM stations farther away more at night due to a condition known as SKIP, or Skywave Propagation. The propagation of AM radio waves changes drastically from daytime to nighttime. This change in AM radio propagation occurs at sunset due to radical shifts in the ionospheric layers, which persist throughout the night. During daytime hours when ionospheric reflection does not occur to any great degree, AM signals travel principally by conduction over the surface of the earth. A condition known as "groundwave" propagation. Useful daytime AM service is generally limited to a radius of no more than about 100 miles, even for the most powerful stations. However, during nighttime hours the AM signals can travel over hundreds of miles by reflection from the ionosphere, a phenomenon called "skywave" propagation. Basically the AM signal bounces off the ionosphere back to the earth rather than traveling in a direct line. This bounce allows the signal to be heard over vast distances. Amateur radio operators call this talking skip.
AM waves are reflected by earth's ionosphere
ionosphere
The Ionosphere
the ionosphere.
ionosphere <novanet>
The ionosphere - specifically the e-layer
Ionosphere
The ionosphere bends radio waves . . . most go out into space, but a fair number hit the earth far away, and are reflected back up to the ionosphere. Radio operators call this phenomenon, "The skip".
Ionosphere
The Ionosphere
Ionosphere.
the lonosphere
The layer of charged particles in Earth's atmosphere is called the ionosphere. The most famous application of this layer is AM radio, which bounces its waves off of the ionosphere for radio receivers to use.