Jet streams are narrow bands of strong winds that flow at high altitudes in the Earth's atmosphere. They typically occur near the top of the troposphere and the bottom of the stratosphere, between 7 and 16 kilometers (4.3 and 9.9 miles) above the surface.

Here's a breakdown:

* High-speed winds: Jet streams can reach speeds of up to 400 kilometers per hour (250 miles per hour).

* Altitudes: They are found at high altitudes, typically in the upper troposphere and lower stratosphere.

There are two main jet streams:

* Polar Jet Stream: Located near the poles, it separates cold polar air from warmer mid-latitude air.

* Subtropical Jet Stream: Located near the tropics, it separates warm tropical air from cooler mid-latitude air.

Jet streams play a significant role in influencing weather patterns, as they steer weather systems across the globe.