What is a jet stream?

What is a jet stream?

• A. A slow current of air near the surface.
• B. A fast following current of air that travels around the planet.
• C. A stagnant air mass above the tropopause.
• D. A wind that only occurs at high latitudes.

Answer: (B)

A jet stream is a fast, narrow band of air high in the Earth's atmosphere that flows around the globe, typically near the tropopause you’d find at the top of the troposphere. These winds arise where there are strong temperature contrasts between air masses, especially between polar and subtropical regions, and they usually move from west to east. Because they’re high up and very fast, they can reach hundreds of kilometers per hour and influence weather and flight routes. They’re not near the surface, not stagnant, and they aren’t limited to the far north or far south; they encircle much of the planet in mid- to high-latitude zones.

A jet stream is a fast, narrow band of air high in the Earth's atmosphere that flows around the globe, typically near the tropopause you’d find at the top of the troposphere. These winds arise where there are strong temperature contrasts between air masses, especially between polar and subtropical regions, and they usually move from west to east. Because they’re high up and very fast, they can reach hundreds of kilometers per hour and influence weather and flight routes. They’re not near the surface, not stagnant, and they aren’t limited to the far north or far south; they encircle much of the planet in mid- to high-latitude zones.