江淮流域持续性强降水过程的多尺度物理模型

本文对江淮流域持续性暴雨事件（PHREs）的多尺度物理模型和能量转换特征以及青藏高原东部对流系统东移影响下游地区降水的研究成果进行了总结。从欧亚大陆Rossby波列能量频散的角度揭示了江淮流域PHREs中纬度系统槽脊稳定的机制，定量分析了冷暖空气的源地和输送路径，提出了江南型和江北型PHREs的多尺度物理模型。从天气尺度和次天气尺度之间的能量转换角度呈现了不同尺度系统相互作用的物理图像，指出背景场的能量供给是直接触发暴雨的次天气尺度系统维持的最重要因子，尤其是在对流层的低层，动能的降尺度级串（即能量由背景场传递给次天气尺度系统）最强。研究表明青藏高原东部对流系统东移影响江淮流域的降水是一系列天气系统配合和活跃的结果，主要由青藏高原和四川盆地、二级地形和东部平原之间的热力环流、西南涡、二级地形以东中尺度涡旋和对流系统的共同影响。除了本文总结的内容，还有一些影响PHREs的因子值得深入研究，多尺度相互作用中的Rossby波源及其波列如何影响天气系统，中尺度系统对其背景场的能量反馈等。

The Multi-scale Physical Model for Persistent Heavy Rainfall Events in the Yangtze-Huaihe River Valley

The multi-scale physical model for persistent heavy rainfall events (PHREs) in the Yangtze-Huaihe River Valley (YHRV), the energy conversion between systems of various scales, and the effects of eastward propagating convection systems from the eastern edge of Tibetan Plateau (TP) on precipitation in regions downstream have been summarized in this paper. To reveal the mechanisms sustaining the quasi-stable middle-latitude troughs and ridges over Eurasia, we analyze the energy dispersion of Rossby waves. The sources of the cold and warm air and their main transport paths are also discussed. The multi-scale physical model for PHREs in the YHRV is proposed. Quantitative calculation of energy conversion between systems of different scales show that the large-scale background circulation is the main energy source maintaining the sub-synoptic and/or mesoscale systems that directly induce heavy precipitation. Energy is transferred from the background circulation to the precipitation-related smaller-scale system through the downscaled energy cascade process of kinetic energy, which maximizes in the lower troposphere. The eastward propagation of convective systems from the eastern edge of the TP to the eastern coastal region is primarily attributed to a series of convective activities associated with several systems from west to east, including the mountain-plain solenoid between the Tibetan Plateau and Sichuan Basin, the southwest vortex, the mountain-plain solenoid between the second-step terrain and the eastern plains, the mesoscale vortexes, and convective systems to the east of the second-step terrain. In addition to the factors summarized in this paper, the PHREs in YHRV are also affected by many other factors, such as the Rossby wave sources associated with the multi-scale interaction, the effects of Rossby waves on synoptic systems, and the energy feedback of the mesoscale systems on their large-scale background circulations. These factors will be investigated further in the future.