The band of wind that travels in the upper troposphere is called the jet stream.

There are two main jet streams in each hemisphere:

* Polar jet stream: Located near the boundary between the cold polar air and the warmer mid-latitude air.

* Subtropical jet stream: Located near the boundary between the warm tropical air and the cooler mid-latitude air.

These jet streams are powerful, fast-moving air currents that play a significant role in weather patterns and global climate.