Lecture 16: Jet Streak, Cyclone structure

Jet streak

Polar front --> a belt of strong north-south temperature contrast

--> large thermal wind --> upper level westerly jet stream

Jet streak: area of stronger wind within the jet stream

Speed of jet streak << wind speed. Reason?

Entrance region: subgeostrophic --> turn left

Exit region: supergeostrophic --> turn right

North-south cross-section

Upward motion in south of the entrance region and north of the exit region

--> preferred areas of storm formation.

Mathematical treatment

Frictional effect

Isallobaric wind

Example

Advective ageostrophic wind

Convergence in the center of