基于S波段双偏振雷达和2DVD雨滴谱仪的华南前汛期强降水微物理特征研究

华南前汛期强降水频发，常导致严重气象灾害。当前对华南前汛期强降水微物理特征科学认识上的匮乏，严重制约了对其发生发展机理的深入研究和数值预报水平的提升。双偏振雷达在获取降水微物理特征上有独特优势，但雷达探测量与雨滴谱分布参数之间存在复杂非线性关系，且有明显地域差异性，难以直接用于降水微物理特征研究。针对上述问题，本研究以广州S波段双偏振雷达为例，首次在华南地区采用多台高精度2DVD雨滴谱仪开展观测试验，获取本地区具有代表性的雨滴谱特征。将雨滴谱特征应用到约束伽马（C-G）模型双偏振雷达反演雨滴谱方案中，建立雷达反射率因子（ZH）和差分反射率（ZDR）与伽马雨滴谱分布三个参数之间的关系，获取准确度较高的雨滴谱时空分布特征。基于双偏振雷达反演雨滴谱结果计算得到降水微物理特征量，将其应用到华南前汛期强降水微物理特征研究工作中，获取典型强降水天气系统不同发展阶段的三维降水微物理结构特征及其演变规律。

During the first rainy season, South China often experiences frequent occurrences of heavy rainfall, leading to severe meteorological disasters. The current lack of scientific understanding of the microphysics characteristics of heavy precipitation over southern China has seriously restricted its mechanism in-depth analysis and the improvement of numerical forecast. The polarimetric radar has unique advantages in obtaining the precipitation microphysics characteristics. However, there are complex nonlinear relationships between the radar observations and raindrop size distribution parameters, which also have obvious regional differences. It`s difficult to carry out the precipitation microphysics characteristics directly based on radar observations. In order to solve the above problems, this study takes the S-band polarimetric radar in Guangzhou as an example. For the first time, many high-precision 2DVD disdrometers are used during field campaign in southern China to obtain the representative characteristics of the raindrop spectrum. The raindrop spectrum characteristics are applied to build up constrained gamma (C-G) model raindrop size distribution retrieval scheme based on polarimetric radar observations. Then, the relationships between radar reflectivity factor (ZH) and differential reflectivity (ZDR) and three gamma raindrop spectrum distribution parameters will be established to obtain high accuracy spatial and temporal distribution characteristics of raindrop size distributions. Based on the raindrop size distribution retrieval results, the microphysics characteristics of precipitation are calculated and applied to the analysis of microphysics characteristics of heavy precipitation over southern China during the pre-summer rainy season. The characteristics and evolutions of three dimensional precipitation microphysical structures in different development stages of typical heavy rainfall systems will be obtained.