CLEAR AIR TURBULENCE AND MOUNTAIN WAVES

1.       For mountain waves to form there should be flow of air across the ridge, generally within ……………of the perpendicular to the ridge.

a.     30° 

b.       45°     

c.       60°

2.       For mountain waves to form the wind speed for small mountains should be atleast

a.      15 m/s

b.      10 m/s

c.    7m/s

3.       For mountain waves to form the wind speed for large mountains should be atleast

a.    15 m/s      

b.      10 m/s 

c.       7m/s

4.       For mountain waves to form the atmosphere should be   up to the ridge, where air stream strikes the ridge.

a.       Unstable    

b.     Stable 

c.      Indifferent

5.       For mountain waves to form the atmosphere should be   at higher levels above the ridge

a.     Unstable 

b.       Stable   

c.       Indifferent

6.       In Mountain waves the Rotor clouds form in

a.       Troughs 

b.    Ridges  

c.       Valley

7.       Clear air turbulence is often encountered

a.      At the boundary of a jet stream

b.      In the wake of a passing airplane

c.      In the wake of a larger airplane at take off and landing

d.    All of the above

8.       Most CAT occurs on the    of a jet stream and in the vicinity of upper level frontal zones where temperature contrasts are strong.

a.     Fringes

b.       Within the core

c.       Axis

9.       CAT is the bumpiness experienced by aircraft at high altitudes    in either cloud-free conditions or in stratiform clouds

a.     above 18,000 feet

b.       below 18,000 feet 

c.       below 28,000 feet

10.   When approaching an area where mountain waves have been reported, a pilot should expect:

a.      Possible presence of roll clouds and lenticular clouds

b.      Intense up drafts and down drafts on the lee side of the mountains

c.      Moderate to severe turbulence as far as 20 to 30 miles from the range on lee side

d.    All of the above