The earth receives tremendous energy from the sun in various forms and in various spectrum.
The most important component of the solar radiation which we receive is the heat energy and light energy as they are really very useful
Solar constant is the measurement of flux.. In layman language it is the quantum of total electromagnetic radiation which is incident or irradiant to the unit surface area of earth in the given Sun-earth mean distance
Thus, solar constant is the measure of flux... flux is a vector describing the amount of heat flow from one unit area to another unit area in a unit time.
Calculating the Solar Constant-
Solar constant can be easily calculated if we know the surface irradiance of Sun. Irradiance is the process in which radiations,electromagnetic are incident on a surface
To calculate the solar Irradiance we need to refer to the Inverse Law
Inverse-square law states that the strength of electromagnetic radiation is inversely proportional to the square of distance between the radiation emitting body and the body receiving it
So,
I= E(4πR^)/4πr^ where
I is the Irradiance at the outer surface of sphere say outer surface of earth
E is the irradiance at the Surface of sun
R is the R is the radius of sun
r is the radius of surface of earth or outer surfaces
Thus we can find the value of E from this equation
Solar constant,So has another formula
So= E(sun)*R^/r^
here ^ is square
R is radius of sun
r is the mean Earth-sun distance or 1AU
E is the irradiance of sun
Thus insolation or amount of solar radiation received on a unit surface area of earth in unit time is I=Scos.Z
z is the zenith angle
Thus earth receives a total Solar constant between 1413-1321 W.m^
Average incoming radiation is solar constant*1/2 cross surface area of sphere,earth
R=(So*1/2πr^) / 4πr^
where So is the solar constant, πr^ is the cross section area of earth and 4πr^ is the TSA of earth
1369/4 ~ 342W/m^
