Visibility and Fog

Question 1

2 examples of ground level visibility are…

Answer 1

RVR and Prevailing visibility

Question 2

3 requirements for the occurrence of blowing sand or dust are …

Answer 2

1) strong winds
2) Dry and loose soil
3) Unstable conditions

Question 3

What type of fog is formed by the process below:

falling rain partially evaporates, saturating the air

Answer 3

Precipitation (Frontal) fog

Question 4

What type of fog is formed by the process below:

moist stable air flows upslope

Answer 4

Upslope fog

Question 5

What type of fog is formed by the process below:

moist air cools over night

Answer 5

Radiation fog

Question 6

What type of fog is formed by the process below:

cool stable air flows over a warm water surface

Answer 6

STeam fog

Question 7

What type of fog is formed by the process below:

Warm moist air flows over a cold surface

Answer 7

Advection warming

Question 8

What type of fog is formed by the process below:

An aircraft lands in very cold, stable air

Answer 8

Ice Fog

Question 9

What type of fog is formed by the process below:

Fog at noon over Alberta with a north east wind

Answer 9

Upslope Fog

Question 10

Radiation fog often thickens at sunrise because

Answer 10

winds increases slightly

Question 11

What is the relationship between the surface temperature (Ts) (not ground temperature) and the dew point (Td) in order to get a good case of advection fog?

Answer 11

Ts<Td

Question 12

Which give the lowest visibility?

Answer 12

snow

Question 13

What is the effect of refractive error when rain streams across a wind screen?

Answer 13

Object appear lower

Question 14

Why is advection fog persistent day and night over water?

Answer 14

Because the water doesn’t cool as fast as the earth.

Question 15

What will form instead of fog if there is a sufficient wind?

Answer 15

clouds

Question 16

How high must one fly in order to see one hundred miles (rounded to nearest 100’)

Answer 16

(100*100) / 1.3 = 7700’ AGL

Question 17

What are the 3 requirements for overcast white out conditions?

Answer 17

1) Uniform overcast
2) Unbroken surface below
3) Diffuse light equally reflected from snow surface and cloud

Question 18

True or False:

In haze, visibility is better when looking toward the sun?

Answer 18

False

Question 19

True or False:

Arctic sea smoke is composed of ice crystal

Answer 19

True

Question 20

True or False:

Air to ground visibility are routinely provided in aviation weather reports

Answer 20

False

Question 21

True or False:

Reduced visibility near the surface is usually associated with low level inversion

Answer 21

True

Question 22

True or False:

Air to ground and ground level visibility in haze will be the same

Answer 22

False

Question 23

True or False:

Slant visual range is the distance on approach that the aircrew can see the horizon

Answer 23

False

Question 24

True or False:

Severe dust storms can reduce visibility to 0

Answer 24

True

Question 25

True or False:

When flying toward a distant mountain in a rain storm the mountain will appear higher than it actually is

Answer 25

False (Lower)

Question 26

True or False:

Light winds will cause radiation fog to thicken

Answer 26

True

Question 27

True or False:

Fog found off the southern shore of Nova Scotia is advection fog

Answer 27

True

Question 28

True or False:

The requirement for arctic sea smoke is very warm air passing over very cold water

Answer 28

False

Question 29

True or False:

Coastal airports in the Arctic are prone to having Arctic sea smoke

Answer 29

True

Question 30

True or False:

Ice fog requires very cold air temperature for its formation

Answer 30

True

Question 31

True or False:

Ice fog results from nocturnal cooling

Answer 31

False

Question 32

True or False:

Frontal fog is most often found behind a cold front

Answer 32

False (ahead of a warm front)

Question 33

True or False:

Arctic white-out occurs under a cloudy sky

Answer 33

True

Question 34

True or False:

The air must be extremely stable for blowing snow to occur

Answer 34

False