Wind

Question 1

What are the fractions of time for occasional, intermittent and continuous turbulence?

Answer 1

Occasional: LESS than 1/3rd of the time

Intermittent: 1/3 - 2/3rds of the time

Continuous: more than 2/3rds of the time

Question 2

How much does IAS fluctuate during light, moderate and severe turbulence?

Answer 2

Light: 5-15kt (<0.5g)

Moderate: 15-25kt (0.5-1.0g)

Severe: >25kt (>1.0g)

Question 3

What is a microburst?

Answer 3

Downburst lasting 2-5mins and less than 4km

Question 4

What is a macroburst?

Answer 4

Larger downburst lasting 5-20mins with more than 5km in area

Question 5

What are the conditions for mountain waves?

Answer 5

• wind speed of at least 15-20kt
• wind direction within 30 degrees perpendicular to the range
• marked stability (inversion)

Question 6

What are the dimensions and speeds of jet streams?

Answer 6

At least 60kt

2000nm long, 200nm wide and 2nm high

Question 7

How does wind velocity change in the friction layer over LAND?

Answer 7

30 degrees between surface wind and geostrophic

50% of geostrophic speed

Question 8

How does wind velocity change in the friction layer over sea?

Answer 8

10 degrees between surface wind and geostrophic

70% of geostrophic speed

Question 9

At what latitude is the POLAR jet steam found?

Answer 9

40 degrees

Question 10

At what latitude is the SUBTROPICAL jet stream found?

Answer 10

25 (winter) - 40 (summer) degrees

Question 11

At what latitude is the TROPICAL (easterly/equatorial) jet stream found?

Answer 11

10-20 degrees