Cosine law of illumination

{
  "id": "MLC-T-MET-004722",
  "term": "Cosine law of illumination",
  "field": "Meteorology and atmospheric science",
  "definition": "A physical law stating that the irradiance, or luminous flux, on a surface is directly proportional to the cosine of the angle of incidence. The angle of incidence is the angle between the incoming radiation and the line perpendicular to the surface (the surface normal). This principle explains why solar radiation is more intense when the sun is directly overhead (low angle of incidence) and less intense at sunrise or sunset (high angle of incidence).",
  "see_also": [
    "Lambert's law"
  ],
  "url": "https://mlchart.com/terminology/meteorology/cosine-law-of-illumination/"
}