Nature and properties of solar radiation

• The surface temperature of the sun is estimated between 55000C and 6100 ⁰C (average 5762 ⁰k).
• The interior temperature ranges from 8*10⁶ to 40*100^{6 0}
• Though sun is not a perfect black body but to some extent it act like so in case of emission. The enormous energy of the sun is produced through the process of nuclear fusion, in which hydrogen is transferred into Helium.
• During the fusion process, some mass is converted into energy; this energy is continuously shedding part of sun’s mass by radiating waves of electromagnetic energy and high energy particles into space.
• This emission represents all the energy available to earth (except for a small amount emitting from the radioactive decay of earth minerals).
• The incoming solar radiation (insolation) that strikes the earth’s surface is that it is equal to about 23-billion horsepower.
• Solar radiation spectrum is illustrated in color bands, including different colors of wave bands commonly referred to as color spectrum