Terrestrial Solar Radiation –
Extraterrestrial Solar Radiation is all of the beam radiation type. Extra Terrestrial Radiation is also known as Direct Radiation. These rays are straight rays from the sun or beams that are unscattered by the atmosphere. The solar energy or sun’s rays falling directly on the earth’s surface is called Terrestrial Radiation.
Terrestrial Solar Radiation is not constant and varies significantly due to the following reasons –
1. Terrestrial Solar Radiation is not constant and varies daily because of the earth’s rotation around the sun.
2. Terrestrial Solar Radiation changes seasonally because of the sun’s declination angle.
3. Terrestrial Solar Radiation changes due to spatial changes between the sun and the earth due to elliptical motion of the earth.
4. During summer, the earth’s axis is tilted towards the sun and northern hemisphere receives more radiation than the southern hemisphere.
5. During winter, the earth’s axis is tilted away from the sun and northern hemisphere receives less radiation than the southern hemisphere.