Question

The spectrum of the Sun as seen on the ground is different from that which arrives that the top of the atmosphere

Answer 1

this is due to atmospheric refraction

Answer 2

The spectrum of the Sun as seen on the ground is different from that which arrives that the top of the atmosphere.

The statement is completely true.

The sun ray which comes to the passes through different layers of the earth's atmosphere.While passing the ray is often reflected, refracted and dispersed through the environnement's elements which generates the ground level spectrums.