The high-altitude winds that occur where trade and polar easterlies meet prevailing westerlies are called jet streams.

Specifically, the subtropical jet stream forms at the boundary between the trade winds and the prevailing westerlies, while the polar jet stream forms at the boundary between the polar easterlies and the prevailing westerlies.

These jet streams are fast-flowing, narrow air currents that circle the globe. They are crucial for weather patterns and are influenced by the temperature difference between the equator and the poles.