Visibility Flashcards
1
Q
What is advection fog?
A
Warm, moist air mass moves over cold surface. Land or Sea, day or night.
2
Q
What is radiation fog?
A
Surface cools by radiation at NIGHT. Then surface cools air by conduction. Occurs on LAND. Little or no cloud cover to limit temp fall. Industrial contamination may provide nuclei.
3
Q
How is RVR defined?
A
It is measured
4
Q
How is prevailing visibility defined?
A
5000m
50%
1500m
