Aridity index

{
  "id": "MLC-T-MET-003630",
  "term": "Aridity index",
  "field": "Meteorology and atmospheric science",
  "definition": "A numerical indicator that quantifies the degree of dryness of a climate at a given location. It is calculated as a ratio of mean annual precipitation to mean annual potential evapotranspiration, which represents the atmospheric demand for moisture. The United Nations Environment Programme defines hyper-arid, arid, semi-arid, and dry sub-humid zones based on specific ranges of this index, with hyper-arid regions having an index below 0.05.",
  "see_also": [
    "index of aridity"
  ],
  "url": "https://mlchart.com/terminology/meteorology/aridity-index/"
}