Solar Irradiance - Definition, Glossary, Details - Oilgae
The amount of solar energy that arrives at a specific area at a specific time - Source
The Earth receives a total amount of radiation determined by its cross section (π·RE²), but as it rotates this energy is distributed across the entire surface area (4·π·RE²). Hence the average incoming solar radiation (called the solar irradiance), taking into account the angle at which the rays strike and that at any one moment half the planet does not receive any solar radiation, is one-fourth the solar constant (approximately 342 W/m²). At any given moment, the amount of Solar radiation received at a location on the Earth's surface depends on the state of the atmosphere and the location's latitude. Source
This Solar Irradiance hits the surface of the earth in two forms, beam (Gb) and diffuse (Gd). The beam component comes directly as irradiance from the sun, while the diffuse component reaches the earth indirectly and is scattered or reflected from the atmosphere or cloud cover.
The total irradiance on a surface is G = GB + Gd (beam and diffuse)
Solar collector: Source
Links
Solar Irradiance and Long-Term Climate Variability:
Total Solar Irradiance - Global warming, Measuring solar irradiance:
