What makes fog?

Question

My son and I were talking about frost and fog. I want some specific and simple explanations for a seven year old of how fog comes to be!

Answer 1

Depends on what type of fog you're talking about. There are a few different types:
Radiation Fog-this fog forms overnight when the ground and lowest 1000ft or so of the atmosphere cool faster than the higher levels. This creats what is called a stable environment, with warmer air over colder air. As long as the winds are light, the skies are clear, and there's enough low level moisture, fog will form in this situation *knocks on wood
Advection Fog-This is simply fog that forms by air moving, or advecting, over a certain type of surface. If you've ever been to the coast and seen the fog roll in off the water, this is what is happening. The relatively warmer air is moving over land, and suddenly it's over a body of water that quite a bit colder than it is. This produces the stable environment again, and fog forms on the body of water and move to the leeward side of it.
Frontal Fog- This happen with warm fronts, since a warm front is sloped in the verticall ahead of the actual front on the surface. The clouds you see ahead of the warm front are forming where the warm air of the front interacts with the cold air, and the frontal boundary on the charts is where the warm air is at the ground. Ahead of the front, you once again have the stable situation, with the warmer air over the colder air. In this case, however, the clouds are above the ground, and the stable clouds produce precipitation. Drizzle can occur in this situation, and when it falls into the cloud layer and hits the ground, it will saturate the lower levels and produce fog.

Sorry if that was a little long. Hope that helps :)

Answer 2

Fog is composed of minute water droplets suspended in the atmosphere and forms near the surface of the earth.These droplets scatter the light rays and the visibility is reduced.When visibility is less than 1000 metres, we call it fog.If the visibility is more than 1000 metres, then it is called mist.Fog is formed (1) when the temperature is reduced below the dew point or (2) when moisture is added to air until condensation occurs.
The conditions favourable for the common type of fog which is called radiation fog are(1) Clear sky(2) light wind (3)presence of sufficient moisture in the air and (4) ground inversion.
In short, the cloud which forms over the ground is called fog.

Answer 3

It starts with the basics: warm air is less dense than cool air, and capable of holding more moisture. When warm air cools rapidly, it condenses quickly (becoming more dense and so sinking) and this causes the moisture particles in the air to stick together - or stick to dust particles or anything else it can. - the idea that fog is just low lying clouds is absolutely right - this is exactly how clouds form as well.
So this is how it happens, what makes it happen? It happens anytime warm air is cooled very quickly - so on a warm day when the temperature drops quickly after the sun goes down - you'll probably see fog. The same thing happens when you exhale on a cold day and see your breath. Or if you open the freezer on a hot day and see the cold air pour out. You're making mini-clouds :-)

Answer 4

There is water vapor in the air and when it air is cooled it condenses. That's what makes dew on the grass and when there is a lot of moisture in the air then cooling makes 'dew' on tiny particles in the air. When it is very near the ground we call it fog. Higher in the sky we call it clouds.

Answer 5

It's when moisture from the ground evaporates (disappears into the air); the evaporated moisture goes up and cools to form fog.

Answer 6

A fog machine.

Answer 7

When the ground or water area is warmer than the air the moisture rises and begins to cool and this moisture in the air is seen because it reflects light

Answer 8

Turn up your thermostat and later open your freezer and show him the fog coming out.

Answer 9

Fog is just low clouds.

Answer 10

intense moisture in the air