Active layer

{
  "id": "MLC-T-MET-003276",
  "term": "Active layer",
  "field": "Meteorology and atmospheric science",
  "definition": "The uppermost layer of ground in permafrost regions that thaws in the summer and refreezes in the winter. Its thickness varies annually and spatially, influenced by factors such as air temperature, vegetation cover, and soil moisture. This layer is distinct from the underlying perennially frozen ground, or permafrost.",
  "synonyms": [
    "frost zone",
    "mollisol"
  ],
  "see_also": [
    "active permafrost"
  ],
  "url": "https://mlchart.com/terminology/meteorology/active-layer/"
}