Question

Q. Consider the following pairs:

Type of fog	Condition required for formation
1. Advection fog	When warm air meets a cooler surface
2. Upslope fog	Orographic uplift
3. Radiation fog	Temperature inversion

Which of the pairs given above is/are correctly matched?

• A.
  1 only
• B.
  2 and 3 only
• C.
  1 and 2 only
• D.
  1, 2 and 3

Answer 1

The correct option is D

1, 2 and 3
Explanation:

Pair 1 is correctly matched: Advection fog forms from surface contact of horizontal winds. When the moist, warm air makes contact with the cooler surface, water vapor condenses to create fog. Advection fog shows up mostly in places where warm, tropical air meets cooler ocean water.

Pair 2 is correctly matched: Upslope fog or hill fog forms when winds blow air up a slope (called orographic uplift). The cooling of the air from rising causes it to meet up with the dew point temperature. This type of Fog forms on top of the mountains.

Pair 3 is correctly matched: Radiation fog is formed in the presence of certain conditions like calm weather, clear sky, and long cool nights. It forms when the ground loses heat at a rapid rate during the night. This makes the air mass above it cooler as well leading to condensation and thereafter formation of radiation fog. This condition is similar to the case of ground level temperature inversion, whereby the colder air mass is near the ground surface and lies underneath the warmer air mass.