海洋中人为碳（anthropogenic CO2）储量及其变化情况，是构建海洋乃至全球碳收支平衡的重要研究内容，对于研究海洋酸化等环境问题具有重要研究和现实意义。南海是我国深度最深、面积最大的边缘海，其北部具有复杂的海气交换和水文动力过程。因此在南海北部，人为碳储量不仅受到海气交换的影响，而且会显著受到水团环流、水团交换等水文过程的影响。基于申请人团队已经具备的氟利昂（chlorofluorocarbons，CFCs）和六氟化硫（sulfur hexafluoride，SF6）的采样方法和同时测定分析技术，本项目拟通过获取南海北部水体中CFCs、SF6的分布，结合温盐等参数，采用转移时间分布（Transit Time Distribution，TTD）方法估算南海北部水体中人为碳的储量；同时通过多次重复站位测量，研究南海北部人为碳储量变化情况及其影响因素，进而探究南海人为碳的源汇问题。

The changes of anthropogenic CO2 in ocean largely affect the carbon cycling in ocean, even the global carbon cycling. It is also important for the in-depth research on marine environmental problems, such as ocean acidification. The South China Sea (SCS) is the largest and deepest marginal sea in China. The complicated hydrological processes (such as currents and water exchange) and air-sea interaction may influence the storage of anthropogenic CO2 in the northern SCS. The storage of anthropogenic CO2 can be estimated by using the transit time distribution (TTD) method with the data of chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6). The sampling method and the simultaneous determination of CFCs and SF6 have been built in the applicants’ lab. So, the distribution of CFCs and SF6 in the northern SCS can be obtained for the estimation of anthropogenic CO2. This study aims to investigate on the change of anthropogenic CO2 and the influence factors in the northern SCS. This will help us to better understand whether the SCS is still a sink of carbon.