夏季江淮切变线结构特征及与暴雨相互作用机制研究

项目名称： 夏季江淮切变线结构特征及与暴雨相互作用机制研究

项目编号： No.41475041

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 姚秀萍

作者单位： 中国气象局气象干部培训学院

项目金额： 90万元

中文摘要： 江淮暴雨是中国夏季最严重的天气灾害之一，常与江淮切变线发生发展相伴随，因此研究江淮切变线与暴雨的相互作用，对于理解江淮暴雨发生发展机制具有重要的科学意义和预报价值。由于观测系统多源资料没有被充分应用和理论上的认识不足，导致对切变线和暴雨相互作用研究不够深入。目前，对切变线研究主要集中在天气分析，理论研究和机制研究甚少。为此，本项目拟采用理论分析、动力诊断和数值模拟相结合方法，重点研究（1）切变线三维动力和热力结构特征；（2）切变线对暴雨影响的动力热力过程和机制；（3）暴雨对切变线的反馈过程和机制。通过建立湿饱和大气广义倾斜涡度发展理论，实现理论创新；通过诊断分析，揭示大气垂直涡度变化与非绝热加热、大气环流、风垂直切变、斜压性和稳定性的内在联系及其对切变线和暴雨发生发展维持的作用，给出非绝热加热对切变线的反馈过程和机制；通过中尺度数值模式进行客观验证，建立切变线和暴雨相互作用的物理概念图像。

中文关键词： 江淮切变线；暴雨；相互作用；机制

英文摘要： The summer rainstorm over the Yangtze-Huaihe River Valley is one of the most important synoptic disasters in China, and it often occurs with the local Shear Line (hereafter, SL). However, the theoretical mechanism of such interaction has not been clearly explored in contrast to the synoptic analysis, due to the limited usage of multi-observational data resources and the poor understanding in the mechanism in the previous studies. Better understanding the mechanism of the interaction between the SL and its related rainstorm will benefit the operational rainstorm forecast. Therefore, on the basis of dynamic, theoretical analysis，and numerical modeling in this project，we intend to discuss the following important scientific issues: 1）the characteristics of the three-dimensional structure of SL, revealed by the dynamical and thermal features ; 2）the physical process and impact of SL on the local rainstorm, and 3）the physical process and the feedback of rainstorm on the SL. Based on the generalization theory of slantwise vorticity on the basis of potential vorticity-potential temperature and the potential vorticity-diabatic heating , we will extend the development of slantwise vorticity theory which much reasonable for those cases to the saturation moist atmosphere. We will reveal the inherent interaction between the SL and rainstorm from the individual term analysis, such as the variation of the vertical vorticity, adiabatic heating, local circulation, vertical shear of the horizontal wind, and the atmospheric baroclinicity and instability. The current study will focus on the impact of these terms on the formation and development of SL and its related rainstorm, and the physical feedback of rainstorm on the SL as well, and we try to present a clear physical explaining for the interactions between SL and local rainstorm after this project.

英文关键词： Shear Line over the Yangtze-Huaihe River Valley;Rainstorm;Interaction;Mechanism