Duct

{
  "id": "MLC-T-MET-005178",
  "term": "Duct",
  "field": "Meteorology and atmospheric science",
  "definition": "A layer in the atmosphere where electromagnetic waves, such as radar signals or radio waves, are trapped and guided, allowing them to propagate over much longer distances than usual. This phenomenon occurs when there is a strong vertical gradient in the refractive index, often due to temperature inversions or sharp humidity changes. Atmospheric ducts can significantly extend the range of radar detection and radio communication.",
  "url": "https://mlchart.com/terminology/meteorology/duct/"
}