Jet stream

Jet streams are fast flowing, relatively narrow air currents found a little below the tropopause, the transition between the troposphere (where temperature decreases with height) and the stratosphere (where temperature increases with height).^[1][2] This is about 10 to 15 kilometres (6.2 to 9.3 mi) above the surface of the Earth.

Animation of the polar jet stream, with the fastest winds in red and slower winds in blue