resources.eumetrain.org: Clear Air Turbulence (CAT), backup Citat: "...Jet streams are intense, relatively narrow, quasi-horizontal currents of wind that are accompanied by strong vertical wind shear. They are found at or near the tropopause. By definition, the wind speed is at least 30 m/s or 60 kt in a jet stream..."
resources.eumetrain.org: Clear Air Turbulence (CAT), backup Citat: "...Jet streams are intense, relatively narrow, quasi-horizontal currents of wind that are accompanied by strong vertical wind shear. They are found at or near the tropopause. By definition, the wind speed is at least 30 m/s or 60 kt in a jet stream..."