Condensation occurs in the atmosphere, in the presence of small particles called condensation nuclei. Any small particles will not do; it is desirable that the particles must have some affinity for water. Hygroscopic materials such as salt and sulphur dioxide then, plays a certain role in the formation of condensate. The present opinion is submitted that the combustion products play an important role in ensuring condensation nuclei and that the size and number of these nuclei are very different. Over the industrial zones can be several million per cubic centimetre of air, whereas, beyond the sea, the density can be several hundred per cubic centimeter.
These kernel play an important role in the formation of rain and fog, but the fog forming cooling moist air, must also take place. There are two common types of mist: the advection fog, formed during the wet sea breeze blowing inland over the cooler surface of the earth, and radiation fog. Radiation fog occurs when moist air is cooled by contact with the ground, which slows down as a result of heat loss by radiation open air.
Cloud cover't encourage heat loss and braking decreasing surface temperature, makes less chance of fog. Still the air is also necessary; any degree of wind usually mist descends quickly. Fog tends to occur in the immediate vicinity of industrial zones at the expense of the local atmosphere was rich in condensation nuclei. In this context, the lack of wind useful in maintaining the concentration of such nuclei. Scattering of nuclei in the future prevents the presence of temperature inversion, that is, the increase of air temperature with increasing altitude, instead of the reverse. It discourages, warm air rises and encourages the combustion products and the fog continues, other factors to be useful.
Long-wave heat radiation, CAO, gazing at the sky at night can be considered black-body radiation with a temperature of absolute zero. It is changed by a correction factor to account for variations in the absorption of water vapor in the lower atmosphere. These changes, as the amount of cloud cover and area of sky visible on the surface varies. According Brant (1932) absorption effect can be accounted for by the steam-and-correction coefficient, K, expressed
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