This phenomenon is specific to the bitter cold. In the Monday, December 24, when the thermometer dropped to -30 degrees, and in some places up to -33, Tver residents observed a surprising phenomenon — small circles halo around the streetlights lighting. The phenomenon was observed at night, the whole city was painted glowing pillars.
As the "KP" Tver State University Rector Andrei Belotserkovskii, this is one of the features of the bitter cold, and this phenomenon is associated with small ice crystals, which, forming in the air, the function of the prism. Their glow and appear bright circle of light, folding in such unusual colored with the column.