Halo of 22°

{
  "id": "MLC-T-MET-006158",
  "term": "Halo of 22°",
  "field": "Meteorology and atmospheric science",
  "definition": "A common optical phenomenon appearing as a circular ring of light with an angular radius of 22 degrees around the sun or moon. It forms when sunlight or moonlight passes through hexagonal ice crystals in high-level cirrus clouds, undergoing refraction. The inner edge of the halo is often reddish, while the outer edge is bluish, due to the dispersion of light.",
  "url": "https://mlchart.com/terminology/meteorology/halo-of-22deg/"
}