It depends on the jet or aircraft you are refering too some go into our atmosphere
The maximum altitude of any military aircraft is dependent on many things including the type of craft. The maximum altitude for a military jet is approximately 60 thousand feet. At that level the flight crew will need special equipment to allow them to breathe and stay conscious in the thin air.
Zero, if the jet plane is on the ground, otherwise it depends at what altitude the plane happens to be flying. Cruising altitude for many passenger airliners is around five to seven miles. Military aircraft often fly at much higher altitudes.
The jet stream regularly affects high altitude wind and low altitude weather.
you mean jet streams...or thermals?
jet streams
The cruising altitude of a normal commercial jet airplane today is around 12,000 m (35,000 ft).
Jet Streams.
8600
It's about 35,000 ft.
Jet stream
The main jet streams are located near the tropopause, the transition between the troposphere (where temperature decreases with altitude) and the stratosphere(where temperature increases with altitude).
The altitude ranges from 30,000 feet to 45000 feet. This is only average altitude. This range is suitable when the plane has levelled.