AM 0 sunlight
Solar @I03254@ in space just above the atmosphere of the earth on a plane perpendicular to the direction of the sun (air mass, AM, zero). Also called extraterrestrial irradiance.
See also:
AM 1 sunlight
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 302 [Terms] [Paper]