The geomorphic air stream which run swiftly at the upper troposphere from west to east with a narrow and meandering course, is called as Jet Stream. During world war ll existence of jet stream was discovered. There is a interesting story behind this discovery of jet stream. During the last phase of world war ll, when the American bomber pilot tried to fly towards Japan at the altitude of 12000m above the sea level, they encountered with a strong wind which reduced their ground speed (sometimes to zero), but when they returned to the east, they noticed the speed became much faster and sometime it became doubled due to high velocity of wind. These pilots were shared their unique experience with high velocity of wind at the upper-level which drew attention to the meteorologists and made them successful to discover this ‘Jet stream’.
Mechanism: Pressure and temperature variation are the main cause of Jet Stream. A very steep pressure gradient is found between sub-tropical high pressure belt and sub- tropical low pressure belt. In the upper layer of atmosphere due to lesser amount of frictional force make the pressure gradient force and coriolis force more or less equal and developed a high speed wind parallel to isobar. This wind is called as ‘Jet stream’.
Read about characteristics of Jet Stream,