Jet stream

A high-altitude (between 9 and 11 km) tubular wind flow at high speed (between 200 and 400 km/h) is responsible for the distribution of pressure at altitude and on the surface. It separates air masses of polar and tropical origin. It can circulate rapidly with a relatively smooth zonal path or more slowly with a strongly undulating path.

Source: Glossary of Terms. National Geographic Institute
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