Variation

{
  "id": "MLC-T-MET-009953",
  "term": "Variation",
  "field": "Meteorology and atmospheric science",
  "definition": "The angular difference between true north, the geographic North Pole, and magnetic north, the direction indicated by a compass needle. This value changes with geographic location and slowly over time due to shifts in the Earth's magnetic field. Aeronautical charts and airport diagrams depict the local magnetic variation, which pilots apply to convert between true and magnetic headings for navigation.",
  "url": "https://mlchart.com/terminology/meteorology/variation/"
}