Final answer:
The polar jet stream is found near the tropopause between the Ferrel and polar cells, affecting weather and climate.
Step-by-step explanation:
The polar jet stream is located near the tropopause between the Ferrel and polar cells. This fast-flowing river of air is found in the upper atmosphere at the boundary between these two atmospheric circulation cells. The jet stream plays a crucial role in determining weather patterns and can have significant impacts on climate conditions.