What is fog?

Question

Over the past few days travelling as been hell due to fog but what is it?

Answer 1

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Fog is a cloud in contact with the ground. Fog differs from other clouds only in that fog touches the surface of the Earth. The same cloud that is not fog on lower ground may be fog where it contacts higher ground such as hilltops or mountain ridges.

The foggiest place in the world is the Grand Banks off the island of Newfoundland, Canada. Fog is frequent here as the Grand Banks is the meeting place of the cold Labrador Current from the north and the much warmer Gulf Stream from the south. The foggiest land areas in the world are Point Reyes, California and Argentia, Newfoundland, both with over 200 foggy days a year.

Most types of fog form when the relative humidity reaches 100% at ground-level. Fog can form suddenly, and can dissipate just as rapidly, depending what side of the dewpoint the temperature is on.

An important exception to the general rule is sea fog. This is due to the peculiar effect of salt. Clouds of all types require minute hygroscopic particles upon which water vapor can condense. Over the ocean surface, the most common particles are salt from salt spray produced by breaking waves. Except in areas of storminess, the most common areas of breaking waves are located near coastlines, hence the greatest densities of airborne salt particles are there. Condensation on salt particles has been observed to occur at humidities as low as 70%, thus fog can occur even in relatively dry air in suitable locations such as the California coast. Typically, such lower humidity fog is preceded by a transparent mistiness along the coastline as condensation competes with evaporation, a phenomenon that is typically noticeable by beachgoers in the afternoon.


During the rainy season, Japan's mountainscapes are often dominated by fog, as seen here along the Kiso Valley.Fog occasionally produces precipitation in the form of drizzle. Drizzle occurs when the humidity of fog attains 100% and the minute cloud droplets begin to coalesce into larger droplets. This can occur when the fog layer is lifted and cooled sufficiently, or when it is forcibly compressed from above. Drizzle becomes freezing drizzle when the temperature at the surface drops below the freezing point.

Answer 2

[ f o g & m i s t : w h a t i s f o g ? ]


Fog is essentially a dense cloud of water droplets, or cloud, that is close to the ground. When night conditions are cold, clear, and calm, the ground releases the heat it absorbed during the day. As the temperature of the ground decreases, it cools the air above it to the dew point (the point at which water vapor condenses into droplets of liquid water), forming a cloud of water droplets known as radiation fog. This is the kind of fog one sometimes sees settling in a valley. Fog also forms when warm, moist air travels over a cold surface. The moisture in the air condenses and forms advection fog, or “land fog.” There is also another type of fog known as sea fog, which is carried from place to place on air currents. This type, which often occurs around San Francisco in the United States, is difficult to dissipate because it continuously forms.

Water droplets are only about 0.01 millimeter in diameter. A dense fog contains about 1200 visible drops per cubic centimeter of empty space - barely enough water to wet an object’s surface.

Answer 3

fog is very low cloud on night conditions that r cold n calm the ground releases heat it absorbed during the day as the temperature of the ground decreases it cools the air above it and we get fog . dont believe me? research on yahoo will help

Answer 4

Fog is the same thing as clouds you see in the sky, just on the ground instead.

Answer 5

Fog is a low flying cloud.

Answer 6

fog is a white mist that fills the air.

Answer 7

Mass of condensed water vapour in the lower air, often greatly reducing visibility.

Answer 8

Think steam. But just outside and very dangerous if not driven through slowly. Oh and it's water vapor.

Answer 9

when the clouds obstruct vision...you seriously never heard of the term its "foggy today?" that's like forecast but i dunno where your from. ok...have you taken a shower, and realized you can't see yourself so well in the mirror? that's fog..you can wipe that kind off...over the past few days...the fog is soo thick outside? that can't be wiped off....hope this is crystal clear....get it??? lol

Answer 10

A ground cloud.