Jet Stream
250 mb isotach
Main Upper Tropospheric Jets
Closely Associated with the
Tropopause
Tropopause
Tropospause Heights
• Tropopause height changes rapidly at
subtropical and polar jets
• Higher in ridges and lower in troughs
Tropopause Height
http://weather.ou.edu/~scavallo/i
mages/real_time/trop_pressure/tr
op_pressure.html
Subtropical Jet Stream
Subtropical Jet Stream Often
Associated with a cloud band
•
http://itg1.meteor.wisc.edu/wxwise/AckermanKnox/chap7/subtropical_jet.html
Jet Stream’s Relationship to
Temperature Can Be Shown
through Thermal Wind
Arguments
250 mb isotach
1000-500 mb thickness-large thickness
gradient and thus thermal wind near jet core
Or alternatively…
The Jet Stream
Recall the horizontal temperature effects
on the pressure:
500 mb
700 mb
850 mb
Warm
Cold
Psurface
The Jet Stream
Consider the balance of forces at each level:
Co
PGF
500 mb
700 mb
850 mb
Warm
Cold
Ps
Other Jets
African Easterly Jet
Sierra Nevada Barrier Jet
There are a variety of jet stream
configurations that are wellknown