Question

The solar spectrum that reaches the surface of the earth is impacted by the gases in the atmosphere due to the wavelength that they absorb​

Answer 1

Because most ultraviolet radiationis absorbed from the solar spectrum and does not reach the earth's surface, the peak of thesolar radiation which reaches the earth's surface is in the visible part of the spectrum. The earth reradiates nearly as a blackbody at a mean temperature of 290 K.

Answer 2

Three atmospheric processes, that is, scattering, absorption, and reflection alter the solar radiation passing through our atmosphere meant for the Earth's surface. These processes have an effect on the radiation when it interacts with suspended particles and gases located in the atmosphere. Explain.

EXPLANATION:

The sun radiates sunlight or solar energy by electromagnetic waves above a continuum of wavelengths defined as the ‘Solar Spectrum’. Three atmospheric processes alter the solar radiation passing via the atmosphere meant for the Earth's surface. These processes have an effect on the radiation when it interacts with suspended particles and gases located in the atmosphere.

The scattering process happens when gas molecules and small particles diffuse part of the solar radiation that is received in random directions sans any modification to the electromagnetic energy’s wavelength. Scattering reduces the quantity of incoming 'solar radiation' which reaches the Earth's surface.

A substantial proportion of shortwave solar radiation that is scattered is re-directed back to space. The extent of scattering which takes place is reliant on the incoming radiation’s wavelength and the size of gas molecule or scattering particle. In the Earth's atmosphere, the existence of numerous particles leads to shorter wavelengths being specifically scattered.

This factor causes the sky to look blue as this colour relates to those wavelengths which are diffused. If scattering does not happen in the atmosphere the sky would be 'black'. If scattering happens, some particles and gases have the facility to absorb 'incoming insolation'.

Atmospheric absorption is the process where the atmospheric particle absorbs the sunlight which is converted into 'heat energy', and then transformed into 'long-wave radiation' emissions which come from that particle. The third process is atmospheric reflection wherein the solar radiation striking an atmospheric particle is re-directed back to space unaltered.  

Sunlight reaching the 'Earth's surface' unchanged by any of the three atmospheric processes is known as direct solar radiation. Solar radiation which reaches the 'Earth's surface' after it was modified by the scattering process is known as diffused solar radiation.