大范围持续性冻雨灾害是中国南方地区冬季一类极端气象灾害，它对当地交通运输、电力传输以及农业等多个方面都造成极其严重的影响。本项研究将总结和归纳中国南方地区不同类型大范围持续性冻雨事件的总体特征；揭示不同类型大范围持续性冻雨事件的中高纬关键环流系统，并阐明该关键环流系统持续维持的动力学机理；基于Rossby 波能量频散理论和分部位涡倾向理论等，深入分析越过青藏高原的天气尺度波对我国华南准静止锋系统的影响以及青藏高原上空低频波列对南支槽和西太平洋副热带高压系统的影响，继而刻画出它们对我国南方大范围持续性冻雨事件的整体影响。本项目的预期研究成果可望为我国南方大范围持续性冻雨事件的预报提供新的依据和思路。

The extensive and persistent freezing rain event (EPFRE) is a kind of extreme weather disaster in winter in southern China. It has a very serious impact on the local transportation, power transmission, agriculture and other aspects. This study attempts to summarize the general characteristics of different types of EPFREs in southern China; reveal key circulation systems over mid- and high latitudes for different types of EPFREs; clarify the dynamic mechanism of the persistence of key circulation system over mid- and high latitudes; analyze in depth the impacts of synoptic scale waves across the Tibetan Plateau on the quasi-stationary front system over southern China and the effects of low-frequency wave trains over the Tibetan Plateau on the trough over the Bay of Bengal and the western Pacific subtropical high, based on theories of Rossby wave energy dispersion and the piecewise tendency diagnostic of potential vorticity, and then finally depict their combined impacts on the EPFREs in southern China. The research outcomes of this project are expected to provide new theoretical basis and clues for the forecast of EPFREs in southern China.