Refractive index

{
  "id": "MLC-T-MET-002294",
  "term": "Refractive index",
  "field": "Meteorology and atmospheric science",
  "definitions": [
    "A dimensionless quantity that describes how fast light travels through a medium compared to its speed in a vacuum, and how much it bends when entering that medium. In the atmosphere, the refractive index of air varies with temperature, pressure, and humidity. This variation causes the bending of light rays, leading to optical phenomena like mirages and the apparent flattening of the sun at the horizon.",
    "A measure of the amount of refraction. Numerically equal to the ratio of wave velocity in a vacuum to a wave speed in the medium, i.e., n = c / v\nwhere: v is actual speed, and c is speed of light in a vacuum."
  ],
  "synonyms": [
    "index of refraction"
  ],
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/refractive-index/"
}