Ljósskil

Ljósskil is an Icelandic term that translates to "light crossing" or "light phenomenon." It is often used to describe various atmospheric optical effects that involve the interaction of light with ice crystals or water droplets in the atmosphere. These phenomena can include a range of visual displays, such as sun dogs, halos, and light pillars.

Sun dogs, also known as parhelia, are bright spots of light that appear on either side of the sun, often accompanied by a halo. They are caused by the refraction of sunlight through hexagonal ice crystals in the atmosphere. Halos are luminous rings that can encircle the sun or moon, and they are also formed by the refraction and reflection of light by ice crystals. Light pillars are vertical shafts of light that extend upwards or downwards from a light source, and they are created by the reflection of light off the flat surfaces of falling ice crystals.

The appearance and visibility of ljósskil depend on several factors, including the size, shape, and orientation of the ice crystals, as well as the position of the sun or moon and the observer. These phenomena are most commonly observed in cold, clear weather conditions when ice crystals are present in the atmosphere. Ljósskil can be quite beautiful and awe-inspiring, and they have been documented and admired by people for centuries. While often associated with winter, they can occur at any time of year when the atmospheric conditions are right.