乌蒙山东侧冰雹云形成机制及催化机理研究

【目的】解决山区冰雹预报及防控技术难题，深入认识复杂山地环境下冰雹灾害天气形成机理。【方法】采用多源观测资料与数值模拟结合，使用乌蒙山东侧雹源地（贵州冰雹防控外场试验基地）布设的垂直观测系统加密观测资料及ERA5高分辨率再分析资料，结合云贵高原下垫面资料，研究了贵州西部冰雹源地的地形影响、环境条件、深对流触发动力因子、云微物理形成和人工防雹催化等方面的特征和机制。【结果】建立了贵州西部冰雹观测数据集；探讨了冰雹源地地形位涡的存在性、演变以及它的产生机制; 分析了雹源地上空不稳定层结条件下深对流触发的动力学特征，发现存在三个加减速关键区：云底加速、云顶加速、下沉减速，上升气流、下沉气流和水汽条件等因素对冰雹增长具有重要影响；对贵州西部一次冰雹过程进行了催化模拟研究，结果表明不同催化高度、催化剂量和催化时间的催化效果存在显著差异，给出了最佳的催化方案。【结论】研究为理解和预测雹暴等深对流的发生发展提供了重要的理论依据，也为实际的防雹作业提供了科学依据。

Research on the Formation Mechanism and Catalytic Mechanism of Hail Clouds in the Eastern Side of Wumeng Mountain

To solve the technical challenges in forecasting and preventing hailstorms in mountainous areas, and gain a deeper understanding of the formation mechanism of hail disaster weather in complex mountain environments, the multi-source observation data and numerical simulations are combined in this research. The multi-source data include the frequently collected observations by the vertical observation system deployed at the hail source in the eastern part of Wumeng Mountain (Guizhou hail prevention and control field test base), the high-resolution ERA5 reanalysis data and the underlying surface data of the Yunnan-Guizhou Plateau. The characteristics and mechanisms of topographic influence, environmental conditions, triggering dynamical factors of deep convection, cloud microphysical formation, and artificial hail suppression are studied and the existence, evolution and production mechanism of topographic potential vorticity at hail sources are discussed. The results are that a dataset of hail observations in western Guizhou Province is established, the dynamic characteristics of deep convection triggering under unstable stratification conditions over the hail source are suggested, with three key acceleration and deceleration regions found: cloud bottom acceleration, cloud top acceleration, and sinking deceleration. Factors such as ascending airflow, sinking airflow and water vapor conditions have important impacts on the growth of hailstones. A catalytic simulation of a hail process in western Guizhou is conducted, and the results show that there are significant differences in the catalytic effects of different catalytic heights, doses, and times. The best catalytic scheme is given. This study could provide an important theoretical support for understanding and predicting the occurrence and development of deep convection such as hailstorms, and also provide scientific guidance for practical hail prevention operations.