Give the properties of Ionosphere.

Ionosphere

1. Ionosphere extends from 80 km to about 480 km.
2. The ionisation of molecules and atoms occurs mainly as a result of ultraviolet rays, X-rays and gama rays.
3. The temperature decreases with increase in elevation until a low point of -100℃ is reached. Beyond this level, the temperature increases again as a result of absorption of short wave solar radiation by the atoms of oxygen.
4. Nitrogen in the extremely rarified air of ionosphere.
5. Ionosphere reflects low frequency radio waves, but absorbs medium and high frequency waves, making it especially important in long distance radio communication.