ESS124
Prof. Jin-Yi Yu
Three Different Jetstreams
double_jet jet
q Subtropical Jet
Located at the higher-latitude end of the Hadley Cell. The jet obtain its maximum wind speed (westerly) due the conservation  of angular momentum.
q Polar Jet
Located at the thermal boundary between the tropical warm air and the polar cold air. The jet obtain its maximum wind speed (westerly) due the latitudinal thermal gradient (thermal wind relation).
(from Atmospheric Circulation Systems)
q Arctic Jet