Question

Q. Consider the following pairs:

Type of fog	Condition required for formation
1. Advection fog	When warm air meets cooler surface air
2. Upslope fog	Orographic uplift
3. Valley 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 air, 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: Valley fog forms where cold dense air settles into the lower parts of a valley, condensing and forming fog. It is often the result of a temperature inversion, with warmer air passing above the valley.