101-4 Wind

Question 1

Convection

Answer 1

Rising air

Hot air rising - convective activity

Question 2

Advection

Answer 2

Horizontal movement of air

Advection fog - wind + fog

Uneven heating of air by contrasting surface temps

Question 3

Pressure Gradient Force

Answer 3

(PGF)
-force that drives winds across isobars & contours from H to L pressures
-difference in pressure stems from diff. In temps (i.e. the greater the temp difference the greater the PGF)

Question 4

Coriolis Force

Answer 4

• Deflection force winds due to earths rotation
• To the right in the Northern Hem.
• Surface friction decreases wind speed & the CF ( little affect above 2000)
• CF has least effect on wind direction @ equator (strongest at poles)

US high alt winds are westerly

Question 5

Wind shear

Answer 5

Rapid change of wind speed/direction over a relatively short distance, time or altitude

Question 6

Vertical Wind Shear

Answer 6

(VWS)
Change in wind speed / change of altitude

If VWS > or equal to 6kts/1000’ = moderate turb
If VWS > or equal to 10kts/1000’ = severe turb

Question 7

Horizontal Wind Shear

Answer 7

(HWS) during cruise
Change of wind speed / distance

If HWS > or equal to 18kts/150nm = moderate
If HWS > or equal to 40kts/150nm = severe

Question 8

KATL @ FL300 has a wind speed of 50kts
KATL @ FL340 has a wind speed of 82kts
What type of turbulence?

Answer 8

8kts = moderate turbulence