Jet Streams

Question 1

What are the dimensions of a jet stream?

Answer 1

winds above 60kts.

length: 1500nm
width: 200nm
depth: 12,000ft
approx 100-200kts

Question 2

What causes a jet stream? and where do they occur?

Answer 2

A large temperature difference between two air masses at FRONTS. therefore occur at transition zone between the cold and warm air tropopauses, the jet core always in the warm air side - but projected ontot he earth surface through the cold air.

Question 3

What are the four jet streams in the NH?

Answer 3

Arctic Jet Stream FL200 (only in winter)
Polar Front FL300
Subtropical FL400
Equatorial FL500 (only in summer) and Flows EAST

Question 4

Artic Jet Stream?

Answer 4

Occurs at boundary between artic and polar air.
Position: 80*N
Speed: 80kts
Alt: 20,000ft

Question 5

Polar Jet Stream?

Answer 5

Occurs at the polar front and follows pattern of polar front depression (zigzag west to east) and varies with the season:
Summer: 50-70N
Winter: 35-50N

alt: 30,000ft
speed: 100-200kts

Question 6

Subtropical Jetstream?

Answer 6

Less variable than PFJS
Position: 30*N
alt: 40,000ft

Question 7

Equatorial Jetstream?

Answer 7

the strange easterly wind that blows only in summer in the NH.

caused by temperature differences in land and sea masses around south east asia/india/tibet.

position: 10-20*N
Alt: 50,000ft
speed: 100kts

Question 8

Polar Night Jetstream?

Answer 8

No interest to pilots, but occurs in stratosphere in winter.

alt: 80,000ft
position: 70* N
spped 100kts