Visibility and Fog Flashcards
2 examples of ground level visibility are…
RVR and Prevailing visibility
3 requirements for the occurrence of blowing sand or dust are …
1) strong winds
2) Dry and loose soil
3) Unstable conditions
What type of fog is formed by the process below:
falling rain partially evaporates, saturating the air
Precipitation (Frontal) fog
What type of fog is formed by the process below:
moist stable air flows upslope
Upslope fog
What type of fog is formed by the process below:
moist air cools over night
Radiation fog
What type of fog is formed by the process below:
cool stable air flows over a warm water surface
STeam fog
What type of fog is formed by the process below:
Warm moist air flows over a cold surface
Advection warming
What type of fog is formed by the process below:
An aircraft lands in very cold, stable air
Ice Fog
What type of fog is formed by the process below:
Fog at noon over Alberta with a north east wind
Upslope Fog
Radiation fog often thickens at sunrise because
winds increases slightly
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?
Ts<Td
Which give the lowest visibility?
snow
What is the effect of refractive error when rain streams across a wind screen?
Object appear lower
Why is advection fog persistent day and night over water?
Because the water doesn’t cool as fast as the earth.
What will form instead of fog if there is a sufficient wind?
clouds
How high must one fly in order to see one hundred miles (rounded to nearest 100’)
(100*100) / 1.3 = 7700’ AGL
What are the 3 requirements for overcast white out conditions?
1) Uniform overcast
2) Unbroken surface below
3) Diffuse light equally reflected from snow surface and cloud
True or False:
In haze, visibility is better when looking toward the sun?
False
True or False:
Arctic sea smoke is composed of ice crystal
True
True or False:
Air to ground visibility are routinely provided in aviation weather reports
False
True or False:
Reduced visibility near the surface is usually associated with low level inversion
True
True or False:
Air to ground and ground level visibility in haze will be the same
False
True or False:
Slant visual range is the distance on approach that the aircrew can see the horizon
False
True or False:
Severe dust storms can reduce visibility to 0
True
True or False:
When flying toward a distant mountain in a rain storm the mountain will appear higher than it actually is
False (Lower)
True or False:
Light winds will cause radiation fog to thicken
True
True or False:
Fog found off the southern shore of Nova Scotia is advection fog
True
True or False:
The requirement for arctic sea smoke is very warm air passing over very cold water
False
True or False:
Coastal airports in the Arctic are prone to having Arctic sea smoke
True
True or False:
Ice fog requires very cold air temperature for its formation
True
True or False:
Ice fog results from nocturnal cooling
False
True or False:
Frontal fog is most often found behind a cold front
False (ahead of a warm front)
True or False:
Arctic white-out occurs under a cloudy sky
True
True or False:
The air must be extremely stable for blowing snow to occur
False
