Geographically possible sunshine duration

{
  "id": "MLC-T-MET-005909",
  "term": "Geographically possible sunshine duration",
  "field": "Meteorology and atmospheric science",
  "definition": "The longest time the Sun could shine on a given day at a place under a perfectly clear sky, allowing for the topographic horizon, so hills and mountains that block the Sun at low angles shorten it. It is shorter than the astronomically possible duration, which assumes a flat open horizon and depends only on latitude and date. Observed sunshine hours are divided by it to give relative sunshine duration as a percentage.",
  "synonyms": [
    "topographically possible sunshine duration"
  ],
  "see_also": [
    "insolation duration"
  ],
  "url": "https://mlchart.com/terminology/meteorology/geographically-possible-sunshine-duration/"
}