中文摘要：

因为它的角色，在水兵和河口环境的溶解的无机的碳(DIC ) 的同位素的作文在决定无机 / 器官的物质和它的应用程序的同位素的作文到各种各样的自然进程的学习较详细地被学习了。海水的 13CDIC 价值被碳和结果的来源和水池在固体之中从同位素分别控制，溶解并且气体的阶段。在这份报纸，基于对在北华南海的溶解的无机的碳的稳定的同位素 geochemical 特征的描述，下列结论被得出：1 ) 自然的水的 13CDIC 价值被碳和结果的来源和水池在固体之中从同位素分别控制，溶解并且气体的阶段。并且北华南海的低海水 13CDIC 价值被海的底层伴随在这个区域的主要生产率；2 ) 根据在 13CDIC 和 PO4 之间的参数关系(13CDIC-1.1 PO4 ) ，北华南海是大气的 CO2 的来源，这被显示；并且 3 ) 氮(N) 和磷(P) 是是浮游植物生长的基础的元素。基于海水 13CDIC 价值和 PO4 和 NO3+NO2 集中的分析，我们 N 是在北华南的限制营养素的数据表演海。

英文摘要：

The isotopic composition of dissolved inorganic carbon （DIC） in marine and estuarine environments has been studied in some detail because of its role in determining the isotopic composition of inorganic/organic matter and its applications to the study of various natural processes. The δ^13DIC values of sea water are controlled by the sources and sinks of carbon and the results from isotope fractionation among solid, dissolved and gaseous phases. In this paper, based on the description of the stable isotope geochemical characteristics of dissolved inorganic carbon in northern South China Sea, the following conclusions were drawn： 1） the δ^13DIC values of natural waters are controlled by the sources and sinks of carbon and the results from isotope fractionation among solid, dissolved and gaseous phases. And the low seawater δ^13DIC values of northern South China Sea are accompanied by a low level of sea primary productivity in this region; 2） according to the parameter relationship （δ^13DIC-1.1 PO4） between δ^13DIC and PO4, it is indicated that northern South China Sea is the source of atmospheric CO2; and 3） nitrogen （N） and phosphorus （P） are the elements which are the basis for phytoplankton growth. Based on the analysis of seawater δ^13DIC values and PO4 and NO3＋NO2 concentrations, our data show that N is a limiting nutrient in northern South China Sea.