Light atmospheric haze

This air light term contributes to the reduced visibility we call atmospheric haze. 

Atmospheric haze is the condition of reduced visibility caused by the presence of fine particles or NO2 in the atmosphere. The particles must be 0.1-1.0 ptm in diameter, the size range in which light scattering occurs. The source of these particles may be natural or anthropogenic. 

Particulate emissions have their greatest impact on terrestrial ecosystems in the vicinity of emissions sources. Ecological alterations may be the result of particulate emissions that include toxic elements. Furthermore, the presence of fine particulates may cause light scattering, known as atmospheric haze, reducing visibility and adversely affecting transport safety, property values, and aesthetics. 

Atmospheric Effects. The presence of fine particles (0.1-1.0 mm in diameter) or N02 in the atmosphere can result in atmospheric haze or reduced visibility due to light scattering by the particles. The major effect of atmospheric haze has been degradation in visual air quality and is of particular concern in areas of scenic beauty, including most of the major national parks such as Great Smoky Mountain, Grand Canyon, Yosemite, and Zion Parks. 

Atmospheric particles are produced in virtually all combustion processes and are also formed when volatile products of plant origin are irradiated in the presence of a light-absorbing species such as NO2. The bluish atmospheric hazes common in forested mountainous areas have been attributed to the latter process. Traces of SOj also promote the formation of organic particulate material. These particles, entering the atmosphere, are the principal locus for PAHs. 

A color-dependent cue arises from atmospheric haze. For large distances of several kilometers, the contrast of a viewed object decreases due to atmospheric scattering of light by floating particles (see Fig. 21). The human visual system takes this effect into account for an ordinal layering of the visible objects [76]. Additionally, Troscianko et al. have found evidence that saturation gradients are able to convey depth information in a similar fashion as texture gradients [77]. 

Fig. 21 Example of atmospheric haze showing contrast attenuation due to scattering of light by atmospheric particles. Thus, more distant hills are rendered desaturated and with less contrast...

Haze (Hazy) an atmospheric aerosol of sufficient concentration to be visible. The particles are so small that they cannot be seen individually, but are still effective attenuating light and reducing visual range. 

When d is expressed in centimeters, y has the units 1/centimeters. For a constant Qext and mass of material, Eq. 16.12 indicates that decreasing the particle size increases the extinction of light for an aerosol. That is, for the same amount of mass, small particles produce more haze in the atmosphere than large particles do. This conclusion is valid only over the range where Qext is essentially constant. For very small particles Qext is strongly dependent on particle size. 

The most prominent feature of Venus middle atmosphere is the global cloud layer that begins at 45 km altitude and extends to 70 km altimde, with thinner hazes 20 km above and below these altitudes. Venus appears yellow-white in visible light, but the first UV images of Venus in the 1920s showed dark or tC-shaped cloud features. The... 

Photochemistry, chemistry caused by light, is responsible for many of the atmospheric reactions that determine the quality of our air. Photochemical smog is the name given to the red-brown haze that can form over cities under certain weather conditions. Nitrogen (as N2) and oxygen... 

The atmosphere becomes milky through light scattering on particles in the size range between 50 and 200 nm. WMO uses for atmospheric obscuration the following terms Fog, Ice fog. Steam fog. Mist, Haze, Smoke, Volcanic ash. Dust, Sand, and Snow. With the exception of smoke, volcanic ash, dust and sand (all these are... 

Sagan and Chyba (1997) [287] proposed that the early Earth had an organic haze layer in its atmosphere. Such a layer can be found in the atmosphere of Titan, the largest satellite of Saturn and is produced by methane photolysis in the presence of nitrogen. An organic haze layer would preferentially absorb ultraviolet light, thereby allowing ammonia and methane to persist in the atmosphere. 

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