Diamond dust appeared in the air of Moscow, which is a rare phenomenon for Central Russia. The smallest ice crystals started floating in the capital’s air, as reported on Thursday, December 23, by the leading employee of the Fobos weather centre Evgeny Tishkovets.
“In conditions of abnormal 20-degree cold and high humidity in the atmosphere, a rare for Central Russia type of solid precipitation is recorded, the diamond dust, a phenomenon in the form of tiny ice crystals floating in the air. In Russian meteorology, this phenomenon is called ‘ice needles’. Diamond dust is usually formed when the sky is clear or almost clear, so it is sometimes also called clear sky precipitation,” Tishkovets explained.
The forecaster specified that this dust is not dangerous for people, but it can create problems for automated airport weather stations when measuring visibility and the lower edge of clouds. It can be seen by the brief flashes that occur when crystals reflect light. According to Tishkovets, unlike fog, which it resembles, dust is formed from ice crystals, not from water. The crystals themselves appear during a temperature inversion when warm and more humid air propagating along the heights mixes with cold air in the lower boundary layer.