江淮流域梅雨的非典型特征成因及其物理机制研究

江淮流域梅雨的降雨量和雨带位置异常会引发严重的灾害，因此研究梅雨落区以及多寡的变化具有重要的现实意义。近期，梅雨出现了非典型特征，包括梅雨降水时空不均匀性显著加大、梅雨雨带南北摆动变大、梅雨期存在高温天气等现象。梅雨的这些非典型特征和传统的梅雨存在较大的差异。然而，关于梅雨非典型特征的变化规律和成因机理，目前的认识还很薄弱。本项目通过资料诊断与数值模式相结合的方式分析江淮流域梅雨非典型变化特征，以及多时间尺度上的成因机制。本项目将聚焦于：1）非典型梅雨锋及其锋面生消变化特征，以及对应大尺度环流的特征；2）探讨海温、北极海冰和青藏高原感热等遥强迫与梅雨非典型特征的关系及相关动力学机制。项目拟揭示梅雨非典型特征的变化规律以及形成机制，为我国梅雨的天气预报和短期气候预测提供科学依据。

The anomalous amount and rainbelt of Meiyu over Yangtze-Huaihe River basin (YHRB) lead to the severe disasters in situ. Thus, it is important to study the amount and rainfall area of Meiyu. Recently, Meiyu appears some new and important characteristics, for instance, the temporal and spatial distribution of precipitation over YHRB become more inhomogeneous significantly, amplitude of Meiyu rianband enlarge, and the hot weather occurs during Meiyu period, etc. These new characteristics of Meiyu, atypical characteristics of Meiyu, differ from the conventional Meiyu rainfall. However, the knowledge of the basic features and mechanisms of Meiyu atypical characteristics are not enough. Based on the diagnose analysis and general climate model simulation, this project will analyze the basic characteristics of Meiyu and the formal mechanism of Meiyu atypical characteristics at multiple time scales. This project focuses on the two key issues: 1) the main features of atypical front and its frontogenesis and frontolysis, and the change features of corresponding large-scales circulations; 2) the relationship between remote forcing (i.e., sea surface temperature, Arctic sea ice and sensible heat in Tibet Plateau) between the Meiyu atypical characteristics and the related dynamics mechanisms. This project will reveal the basic features and formation mechanisms of Meiyu atypical characteristics, in order to provide scientific evidences for weather forecast and short-term climate prediction of Meiyu.