Short notes on the Classification on the Basis of Appearance

Difference terms are used to indicate fogs formed under different conditions. Some of the fog names are described below:-

Smog:

In the polluted air of large industrial centers the air contains a large number of soot and dust particles, many of which are hygroscopic having a high affinity to water vapour. The fogs produced in these areas are dirty and mixed with smoke.

Such a type of fog is called smog (smoke + fog). The smog or pea-soup fog of the industrial town of London has gained notoriety as an environmental hazard.

Because of the presence of excessive smoke near the ground, the warming of earth's surface by the rays of sun is retarded. Therefore such fogs persist for several days making life difficult.

Smaze:

This name is given to a fog which is an admixture of smoke and haze.

Frost-smoke:

In the Arctic region, when air temperature falls much below the freezing point and even then the water in sea and bays is not allowed to freeze, a kind of fog consisting of innumerable ice particles and super-cooled water droplets is formed by the process of condensation taking place on the surface of those water bodies.

Such a fog is called frost-smoke. These fogs are carried over the land by winds. In the mountain regions of North America, these fogs are called 'pogonip'. In Siberia and North Canada, such fogs form at a temperature ranging from -30° to -50°C in winter.