Question

The phenomena involved in the reflection of radio waves by ionosphere is similar to or not as the total internal reflection of light in air during a mirage.

Answer 1

As we know, when radio waves travel up in the atmosphere, they undergo multiple refractions away from the normal as the optical density of air keeps on reducing (in general). At the ionosphere, they reach the critical angle. Then, the phenomenon is known as total internal reflection.

Now, when the radio waves travel downwards and undergoes multiple refractions, the radio wave again and again moves towards the normal as the optical density of air increases as it goes towards the earth.

The optical illusion known as Mirage, in this warmer air has less refractive index than cooler air. On a hot day, air near the ground is hotter than above. Hence the refractive index decreases progressively towards the ground.

Light emanating from an object bends away from the normal progressively. At one point, the angle of incidence is larger than the critical angle to cause total internal reflection. This results into inverted image to be formed on the ground of the light source. This gives the illusion of water.

Final Answer: Similar.