Heterosphere

{
  "id": "MLC-T-MET-006233",
  "term": "Heterosphere",
  "field": "Meteorology and atmospheric science",
  "definition": "The region of the Earth's atmosphere above approximately 80 to 100 kilometers, where atmospheric gases are stratified by molecular weight rather than being uniformly mixed. In this layer, heavier gases like oxygen and nitrogen settle to lower altitudes, while lighter gases such as helium and hydrogen become more prevalent at higher altitudes. This stratification is due to molecular diffusion dominating over turbulent mixing.",
  "see_also": [
    "atmospheric shell"
  ],
  "url": "https://mlchart.com/terminology/meteorology/heterosphere/"
}