The Meteorological Conditions and Dynamic Mechanisms Responsible for the Freezing Rain and Snow Inducing Zhejiang Power Grid Icing Disaster

The power grid icing disaster frequently occurs in recent year, induced by freezing rain and snow weather. In this study, we analyze the meteorological conditions and dynamic mechanism responsible for the extreme event of freezing rain and snow in Zhejiang province, causing extensive icing of transmission line. Besides large-scale circulation anomaly, the frontal circulation and inversion layer are key factors to maintain freezing rain. Frontogenesis function and Richardson number explain why the front maintains for such a long period and how the unstable layer is built up, providing possible dynamical attribution for the case. These researches help us to take preventive measures in advance, and seek effective ways to reduce freezing rain/snow-induced power grid icing disasters.