青藏高原热源与天气系统影响我国灾害性天气的机理研究

In this project, by using datasets from operational observation network, scientific observation stations over the Tibetan Plateau and its surroundings, intensive observation experiments, global reanalysis data, retrieved data from satellite measurements and radar, a thorough and systematic study of the characteristic, mechanism and prediction of the disaster weather such as torrential rain affected by the heat source and the weather systems over the Tibetan Plateau is conducted, through the analysis and diagnosis of observations and field experiments data, numerical simulation, and theoretical analysis, especially the OSSE, the numerical model of WRF, intensive observation and the multi-scale comprehensive diagnosis of energy and wave. It is mainly concerned: spatial and temporal structure of disaster weather affected by the heat source of the Tibetan Plateau; variations of weather systems such as plateau vortex and Southwest China vortex over the Tibetan Plateau, interactions between them and its weather influence; theory and technology of the forecasting for Plateau affecting disaster weather. This project will find the key regions of heat source and weather system evolution over the Tibetan Plateau and its surroundings; understand the structure characteristics of weather systems over the plateau and the mechanism of the evolution and eastward movement of it; elucidate the physical processes and cause of disaster weather affected by the heat source and weather systems over the Tibetan Plateau; propose forecasting theory and technology of disaster weather such as torrential rain based on the strong signal of the key regions over the Tibetan Plateau. Thus further improve the forecasting skills of disaster weather-climate in China.

基于青藏高原及周边地区业务站网、科研站点资料，加密观测试验、国际再分析资料，卫星与雷达反演资料，通过观测分析、试验验证、诊断研究、数值模拟和理论分析，尤其是OSSE试验，新一代WRF数值模式，时空加密观测，多尺度能量与波动综合诊断等关键技术，深入系统地研究青藏高原热源与天气系统影响我国暴雨等灾害性天气的特征、机理及其预测。通过青藏高原热源影响灾害性天气的时空结构、高原涡和西南涡等高原天气系统变化与相互作用及其天气影响、青藏高原影响灾害性天气预报理论与技术等重点研究内容，辨析青藏高原及周边地区热源、天气系统演变的关键区；认识高原天气系统结构特征及其发生发展与东移机理；阐明高原热源和天气系统影响灾害性天气的物理过程与形成原因；提出基于高原关键区强信号影响的暴雨等灾害性天气预报理论与技术。由此进一步提升我国灾害性天气气候预报能力。

青藏高原地-气过程对我国、亚洲、北半球乃至全球的天气气候及环境变化都有着重要的影响，尤其是在我国灾害性天气气候演变中起着非常独特的作用。如1998年夏季我国长江全流域的特大暴雨洪涝灾害，2008年冬季我国南方50年一遇的冰冻雨雪灾害等。因此，本项目基于多源观测试验资料，通过观测分析、试验验证、诊断研究、数值模拟和理论分析，针对青藏高原热源与高原天气系统对我国灾害性天气的重要影响，研究了青藏高原热源与天气系统的时空分布结构、青藏高原热源演变特征与灾害天气影响、青藏高原天气系统活动与灾害天气、高原影响灾害性天气的预报理论与关键技术，取得了新的成果。主要包括：分析高原热源异常、高原天气系统活动的区域分布与结构，青藏高原及周边地区的热源和天气系统活动区域及其相互关系，辨析了青藏高原及周边地区热源、高原涡与西南涡演变的关键区及其物理联系；研究高原涡、西南涡等天气系统的基本特征、演变过程、物理成因，揭示了高原涡、西南涡的结构特征及其发生发展与东移机理；分析高原热源、高原涡、西南涡作用下，我国暴雨等灾害性天气的异常过程与形成原因，发展了基于青藏高原关键区强信号重要影响的暴雨等灾害性天气预报理论与技术。并且，基于青藏高原及周边地区业务、科研站网，成功开展了高原天气系统加密观测大气试验，捕捉到高原天气系统演变及其影响的完整变化，取得了宝贵的高分辨率“过程观测”资料，在科学研究、预报业务中发挥了有效作用，建立了观测试验与天气预报互动的低涡暴雨预报新技术。总之，项目围绕高原热源与天气系统影响我国灾害性天气的科学问题，在观测试验、理论研究、业务技术等方面，进一步加深了青藏高原对我国灾害性天气影响的系统认识，提升了灾害性天气的预测预报能力，具有重要的理论意义和应用价值。