Ice crystals in the atmosphere create glowing spots on both sides of the Sun, called sundogs.Ī sundog, also known as sun dog, mock sun or parhelion, consists of glowing spots around the sun. However, they are more often seen in the winter months because the cold weather creates better conditions for the formation of halo-generating ice crystals.Ģ2-degree halos are formed when light passing through an ice crystal bends 22 degrees, while 46-degree halos occur when the light bends 46 degrees. In general, halos can be seen throughout the year, around the world. Two kinds of halos are most commonly observed from Earth – the 22-degree and the 46-degree halos. The Different Kinds of Atmospheric Phenomena Halos On the other hand, column-shaped ice crystals tend to float in the air vertically. Plate-shaped crystals float in the air horizontally like a leaf. In addition to the shape of the ice crystals and the angle between the facets, the orientation of the ice crystals also determines the kind of optical phenomenon that will be created. Because of this, scientists who study atmospheric optical phenomena classify them as 60-degree or 90-degree phenomena. Halos and other optical phenomena are created because of the interplay between the shape of the ice crystals and the angle between their facets. While the molecular structure of ice crystals is always hexagonal, their shape can vary from a flat plate to a column. These crystals are known as diamond dust. Sometimes, in very cold weather, ice crystals form very close to the Earth’s surface. Generally, these crystals, which have a hexagonal molecular structure, are found in the cirrus clouds. Ice crystals can be found high up in the sky all around the world, at any time of the year. On the other hand, refraction occurs when light enters an object and bends.Īstronomical terms & definitions Ice Crystals

Reflection occurs when light bounces off the surface of an object. It also depends on whether the light is reflected or refracted by the ice crystals. The size, shape, and distance from the Earth’s surface of the ice crystals determine what kind of optical phenomenon people on Earth will observe. Business Date to Date (exclude holidays)Ī Sun halo seen from Lofoten Islands, Norway.

Light phenomena examples