Natural Phenomenon

Light Pillars

Light pillars are several pillars formed by light of sun which appear when the temperature of the weather is about 4 celsius degree in polar area. It seems as if a light of pillars which appear from the ground to the sky. Sometimes during very cold weather, vertical columns of light beaming directly upwards are visible. These are called light pillars and are created by the reflection of light from ice crystals with near horizontal parallel planar surfaces. The light can come from the Sun (usually at or low to the horizon) in which case the phenomenon is called a sun pillar or solar pillar. It can also come from the Moon or from terrestrial sources such as streetlights. Light pillars are typically seen in polar of regions.

Light pillars appear when artificial light or natural light bounces off the facets of flat ice crystals wafting relatively close to the ground. When the light source is close to the ground, the light pillar appears above the floating crystals. When the light comes from the sun or moon, the light pillar can appear beneath them, too, as the light refracts through the crystals.

A light pillar is a visual phenomenon created by the reflection of the light from the ice crystals with near the horizontal parallel planar surfaces. The light can come from the sun (usually at or low to the horizon) in which case the phenomenon is called a sun pillar or solar pillar. It can also come from the moon or from terrestrial sources sun light pillars are a kind of optical phenomenon which is formed by the reflection of sunlight or moonlight by ice crystals that are present in the Earth's atmosphere. They are also called the crystal beam phenomenon.

 

The light pillar looks like a thin column that extends vertically above and/or below the source of light. The light pillar is prominently visible when the Sun is low or lies below the horizon. It normally forms an arc that extends from five to ten degrees beyond the solar disc. Light pillars can sometimes also be seen arising from the Moon.

 

Light pillars are formed by reflection from ice crystals with roughly horizontal faces.

Light pillars have also been known to produce UFO reports. Niagara Falls is one such area, where the mist from the Niagara Falls causes the phenomenon to appear frequently during the winter months, where the ice crystals interact with the city's many upward facing spotlights to create prominent light pillars. Light pillars could also be formed by man-made light sources, such as streetlights.

A light pillar, or sun pillar, appears as a vertical pillar or column of light rising from the sun near sunset or sunrise, though it can appear below the sun, particularly if the observer is at a high elevation or altitude. Hexagonal plate- and column-shaped ice crystals cause the phenomenon. Plate crystals generally cause pillars only when the sun is within 6 degrees of the horizon, or below it; column crystals can cause a pillar when the sun is as high as 20 degrees above the horizon. The crystals tend to orient themselves near-horizontally as they fall or float through the air, and the width and visibility of a sun pillar depends on crystal alignment.

 

          Light pillars can also form around the moon, and around street lights or other bright lights. Pillars forming from ground-based light sources may appear much taller than those associated with the sun or moon. Since the observer is closer to the light source, crystal orientation matters less in the formation of these pillars.

Sources of the images         :https://www.google.com/search?q=light+pillars&tbm=isch&tbo=u&source=univ&sa=X&ei=s8PcVPmIEpPjuQTa-YDgBw&ved=0CC0QsAQ&biw=1366&bih=667

References                                  :http://www.atoptics.co.uk/halo/lpil.htm