Atmosphere Contents

5. General Circulation

Jet streams form at higher altitudes in the mid latitudes

At higher altitudes, the westerly flow is much more steady in direction and speed, reaching a maximum in the jet streams at altitudes of 10 to 15 km. These air currents are thousands of kilometres long, a few hundred kilometres wide and only a few kilometres thick. There are two jet streams, the subtropical jet stream situated above the subtropical high and the polar front jet stream situated at high altitudes near the polar front. Both of these jet streams are located at the tropopause, hence they are referred to as tropopause jets and allow mixing between tropospheric and stratospheric air.

Stratosphere

What are jet streams?