Circumpolar whirl

{
  "id": "MLC-T-MET-004311",
  "term": "Circumpolar whirl",
  "field": "Meteorology and atmospheric science",
  "definition": "A large-scale, persistent cyclonic circulation of air that encircles the Earth's polar regions in the middle and upper troposphere and stratosphere. This vortex is strongest in winter and weakens in summer, driven by temperature differences between the pole and lower latitudes. Its strength and stability influence the trajectory of weather systems in the mid-latitudes.",
  "url": "https://mlchart.com/terminology/meteorology/circumpolar-whirl/"
}