Diurnal variation of solar irradiance

Diurnal Variation Solar Radiation

For a given set of atmospheric conditions, the irradiance at any point on the Earth's surface is determined by the solar elevation, b. This rises during the day from zero (or its minimum value in the Arctic or Antarctic during the summer) at dawn to its maximum value at noon, and then diminishes in a precisely symmetrical manner to zero (or the minimum value) at dusk. The exact manner of the variation of b with time of day depends on the latitude, and on the solar declination, d, at the time....