The jet stream is a narrow band of fast-moving air above the Earth’s surface at a height of 10 to 15 kilometers. These winds blow in a westerly direction and are responsible for weather phenomena. There are two jet streams, located above the Northern and Southern Hemispheres.
The position of the jet stream can change rapidly depending on various factors, such as changes in temperature and pressure. Freak weather phenomena have been associated with changes in the position of the jet stream.
Two main masses of air from the tropics and from the poles affect the strength and position of the jet stream. The air mass from the tropics is warm, while the air mass from the poles is very cold.