Emission line

{
  "id": "MLC-T-MET-005358",
  "term": "Emission line",
  "field": "Meteorology and atmospheric science",
  "definition": "A narrow, bright band of electromagnetic radiation at a specific wavelength, produced when an excited atom or molecule transitions from a higher energy state to a lower one. In atmospheric science, these lines are observed in the spectra of atmospheric gases, providing information about their composition, temperature, and density. The sodium D-line is a prominent example in the mesosphere.",
  "url": "https://mlchart.com/terminology/meteorology/emission-line/"
}