Nature Phenomenon

 

Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates obscure the clarity of the sky. Includes a classification of horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic ash, dust, sand, and snow. Sources for haze particles include farming (ploughing in dry weather), traffic, industry, and wildfires.

Seen from afar and depending on the direction of view with respect to the Sun, haze may appear brownish or bluish, while mist tends to be bluish grey. Whereas haze often is thought of as a phenomenon of dry air, mist formation is a phenomenon of humid air. However, haze particles may act as condensation nuclei for the subsequent formation of mist droplets; such forms of haze are known as "wet haze."

In meteorological literature, the word haze is generally used to denote visibility-reducing aerosols of the wet type. Such aerosols commonly arise from complex chemical reactions that occur as sulfur dioxide gases emitted during combustion are converted into small droplets of sulfuric acid. The reactions are enhanced in the presence of sunlight, high relative humidity, and stagnant air flow. A small component of wet-haze aerosols appear to be derived from compounds released by trees, such as terpenes. Large areas of haze covering many thousands of kilometers may be produced under favorable conditions when summer in north earth countries.

Obscuration

Haze causes issues in the area of terrestrial photography, where the penetration of large amounts of dense atmosphere may be necessary to image distant subjects. This results in the visual effect of a loss of contrast in the subject, due to the effect of light scattering through the haze particles. For these reasons, sunrise and sunset colors appear subdued on hazy days, and stars may be obscured at night. In some cases, attenuation by haze is so great that, toward sunset, the sun disappears altogether before reaching the horizon.

Haze can be defined as an aerial form of the Tyndall effect therefore unlike other atmospheric effects such as cloud and fog, haze is spectrally selective: shorter (blue) wavelengths are scattered more, and longer (red/infrared) wavelengths are scattered less. For this reason, many super-telephoto lenses often incorporate yellow filters or coatings to enhance image contrast.