What actually causes fog.?

Question

What actually causes fog.?

Answer 1

when the water vapor is saturated and the air is cold enough then can not hold more of the vapor then it can be visible which is called fog ,some times low stratus clouds can be reported as fog .normally fog formed in morning when surface is cold and wind is calm during night...that's all came to my mind now/good luck

Answer 2

Fog can be considered a cloud at ground level. The processes forming it, however, are usually different from those that form clouds. Like clouds, fog is made up of condensed water droplets which is the result of the air being cooled to the point (actually, the dewpoint) where it can no longer hold all of the water vapor it contains. For clouds, that cooling is from the rising of air parcels, which cools from expansion. For fog, which occurs next to the ground, there are usually other reasons for this cooling. For instance, rain can cool and moisten the air near the surface until fog forms. Also, infrared cooling of a cloud-free, humid air mass at night can lead to fog formation - this is called "radiation fog". Radiation fog is most common in the fall, when nights get longer, and land and water surfaces that have warmed up during the summer are still evaporating alot of water into the atmosphere. Finally, a warm moist air mass blowing over a cold surface (usually snow or ice) can also cause fog to form-this is called "advection fog".

Answer 3

Warm moist air can move in from the sea and meet with cool dry air over land. The result is when the vapor condenses into tiny water droplets that hang low to the ground. Sea fog is just the opposite. Cool dry air moves over warm moist air over the water.

Answer 4

Fog is nothing but a cloud on ground.Fog is composed of minute water droplets  suspended in the atmosphere.Fog is formed (1) when the temperature is reduced below the dew point temperature or (2) when moisture is added to air until condensation takes place.Examples are given below.

Radiation fog is an example of the first case above mentioned.Loss of heat by radiation of energy into space is the principal factor in the formation of this type of fog.Due to loss of heat,air temperature comes down to reach dew point temperature and fog forms.The conditions favourable for the formation of this type of fog are(1) presence of sufficient moisture in the air(2)light wind (3) clear skies and (4) ground inversion.

Coastal fog which is one type of advection fog is an example for the second case above mentioned.When moist air from the sea moves over the adjoining colder land,moisture is added to the air resulting in the formation of this type of fog.