What does solar constant mean?
- RaymondLv 77 years agoFavorite Answer
The flux of energy that arrives from the Sun, at Earth's distance from the Sun (1 AU)
it is approximately 1.36 to 1.37 kW/m²
This is measured perpendicular to the direction of the flux (imagine holding a 1 square-metre panel directly facing the Sun), in space - before Earth's atmosphere has any effect on it (our atmosphere, clouds and snow will bouncs, on average, 37% of that back into space).
The constant varies (every so slightly) over the 11-year cycle of activity of the Sun.
The actual flux will vary according to Earth's position along its orbit (perihelion vs aphelion).
It is called a "constant" because it can easily be used to calculate the flux to any other object, once you know its distance from the Sun in Astronomical Units (AU).