冬季西太平洋副热带高压活动年际变异机理研究

近年来，我国南方频繁发生严重的低温雨雪冰冻气候灾害，极大程度影响了我国社会经济的发展。冬季西太平洋副热带高压活动异常是造成我国冬季气候变异的重要成因之一，但由于冬季西太平洋副热带高压活动的年际变异机理尚不明确，极大程度制约了我国冬季气候预测发展潜力。本项目在我们前期提出的西太平洋副热带高压动力学指数基础上，应用统计诊断、简化理论分析及数值模拟相结合的方法，分析冬季西太平洋副热带高压活动时空变异特征及其在年际尺度上与热带海洋、北半球积雪等外源强迫异常配置的关联，获得影响冬季西太平洋副热带高压活动年际变化的关键因子；诊断热带海洋、北半球积雪等外源强迫等外源强迫配置异常导致大气内部动力和热力过程差异，进而影响冬季西太平洋副热带高压活动年际变异关键物理过程；揭示造成冬季西太平洋副热带高压年际变异的机理，可为提高我国冬季气候预测能力，满足国家防灾减灾重大需求提供可靠的理论依据。

In recent years, severe cold rain and snow-freezing climate disasters frequently occur in the south of our country, which has a greatly bad effect on the development of our country's society and economy. The abnormal phenomenon of the western pacific subtropical high activity in winter is one of the important causes of the variation of the winter climate in China. However, the interannual variation mechanism of the western pacific subtropical high activity in winter is still unclear, which greatly restricts the development potential of the winter climate forecast in China. On the basis of the dynamic index of western pacific subtropical high, the methods of statistical diagnosis, simplified theoretical model and numerical simulation is used to analyze the temporal and spatial variability of western pacific subtropical high activity in winter and the correlation between the temporal and spatial variability of the winter western pacific subtropical high activity and the external forcings anomalies such as tropical oceans and snow cover in the northern hemisphere at interannual time scale, and the key factors that affect the interannual variation of western pacific subtropical high activity in winter; The external forcing such as tropical ocean and northern hemisphere snow cover and their configurations impact on the difference of atmospheric internal dynamic and thermal processes, and further influence on interannual variation of western pacific subtropical high activity in winter will be diagnosed. The mechanism for the interannual variability of variation of winter western pacific subtropical high activity will be revealed in this study. The results of this study will provide a reliable theoretical basis for improving the forecasting ability of winter climate in China and satisfy the important demand of national disaster prevention and reduction.