西北太平洋台风活动对中国天气和气候有重要影响，探索其年际变率特征及形成机理至关重要。研究表明，季风槽、副高等多个气候因子对台风活动年际变率有共同调控作用，但这些气候因子之间相互作用，共同调控的细节和物理机制目前尚不清楚。本项目拟结合资料分析、动力诊断、理论模型和大气环流数值试验等方法，将印度洋和西太平洋区域作为一个整体，研究春季和夏季印度洋-太平洋暖池区域Hadley环流(IPWP_HC)年际变率主导模态对西北太平洋台风活动的影响，揭示其协调不同气候因子共同影响台风活动的物理机制，阐明春季和夏季IPWP_HC年际变率主导模态对西北太平洋台风活动影响的相对贡献，建立相应的物理概念模型。项目研究将为西北太平洋台风活动的短期气候预测提供科学依据，同时为认识西北太平洋台风活动年际变化规律提供一个新的视角。

The interannual variability of Western North Pacific (WNP) typhoon activity has important influence on China weather and climate, thus investigating the characteristics of its interannual variability and mechanisms is important. Previous studies shows that multiple climate factors can interact with each other and modulate the typhoon activity. But it is unclear that how they interact with each other and influence the typhoon collaboratively. Combined with data analysis, dynamical diagnostics, theoretical models and general circulation numerical experiments, the current project tries to discuss the influence of principal modes of the Indo-Pacific Warm pool regional Hadley circulation (IPWP_HC) on the WNP typhoon activity, reveal the physical processes on how the spring and summer IPWP_HC principal modes collaborated with key climate factors and influence the typhoon activity, elucidate the relative contribution on spring and summer IPWP_HC principal modes on the WNP typhoon activity and propose the physical concept model on how IPWP_HC principal modes influence the WNP typhoon activity. The successful implementation of the project will provide scientific basis for WNP typhoon short-term climate prediction and a new angle of view on the interannual variability of WNP typhoon activity.