diffuse solar radiation
Technical term in meteorology and solar energy; refers to the amount of solar radiation scattered by the atmosphere and arriving at the surface from directions other than the direct solar beam.
See also: 日射量
Diffuse solar radiation contributes to power generation even on cloudy days.
日射量 is the general term for solar irradiance, while 散乱日射量 specifically refers to the diffuse component.
Compound of 散乱 (scattering) + 日射量 (solar irradiance). The exact historical derivation is uncertain; the term is a modern technical coinage.