南海风生上升流和下降流是南海表层和底层物质能量交换的重要渠道，对生态系统和碳循环有着重要的影响。本项目将立足于南海航次和岸基观测资料及高时空分辨率再分析资料，结合统计分析及诊断等方法，建立上升流和下降流风生动力指数UI和CUI，研究南海风生季节性上升流和下降流开始时间、结束时间、持续时间、最强时间和累积强度的演变特征，揭示风生上升流和下降流对不同ENSO类型、PDO等的响应机制，探讨在全球增暖背景下南海风生上升流和下降流的长期变化趋势，增强对南海沿岸上升流和下降流的认识。

The upwelling and downwelling along the coast of South China Sea (SCS) are important channels for material and energy exchange between the upper and bottom layers. They play important roles in ecological fishery and climate change by adjusting the nutrient fluxes and carbon cycle. The goal of this proposal is to evaluate spatial and temporal variability on the onset, duration and intensity of upwelling and downwelling in the SCS. Using datasets from SCS observed network and high-resolution reanalysis, the life-cycle and cumulative intensity of upwelling and downwelling along the SCS are estimated, and examine the spatial variation over the SCS, from the Vietnam coast to east Guangdong. Finally, the response of wind-drived upwelling and downwelling to the ENSO, IOD, global climate change are investigated, and the change of atmospheric circulation associated with the variability of upwelling and downwelling are examined. The results will be helpful for better understand and predict the evolution of upwelling and downwelling along the SCS.