基于第一岛链内国内外海水温度、实用盐度、TCO2、DOC、pH、硝酸盐、亚硝酸盐、硅酸盐、碱度等海洋水文数据和海水溶解成分数据，通过数据统计、客观分析、可视化图表分析，分析确定该海域海水成分分布特征和季节变化规律；基于以上结果，利用海水热力学方程-2010计算海水绝对盐度（溶解物质的质量分数）的经验公式，以及Pawlowicz（2010）计算海水盐度的公式，构建拟合中国近海海洋成分模型和绝对盐度计算公式；搭载国家海洋局常规断面调查和国家专项调查，针对中国近海海水密度和相关主要海水成分的进行集中测量，实现对中国绝对盐度计算公式的验证、修定和最终确立。通过项目实施，精确表征中国近海复杂多变的水文和化学环境，提高该海域海水热力学属性计算的精度和准确度，为中国近海海洋环境开发和海洋环境保护提供相应的热力学和动力支撑。

Distribution characteristics and seasonal variation of seawater composition of the China sea will be analyzed and identified through data statistics, objective analysis, visual plot analysis based on the oceanographic and dissolved substance data of sea temperature, practical salinity, TCO2, DOC, pH, nitrate, nitrite, silicate, alkalinity, etc. and the of sea water. The project, based on the above analysis results, will apply thermodynamic equation of seawater -2010 for calculating absolute salinity of seawater (mass fraction of dissolved substances) and Pawlowicz（2010）formulas for calculating seawater salinity to establish sea water ingredients model and fit the formulas to calculate absolute salinity in the study area, and verify, revise and accomplish the formulas by use of the ocean density and salinity data from conventional cross-sectional survey of State Oceanic Administration. The project will be able to actually present the hydrographic and chemical environment of Chinese offshore waters, improve the precision and accuracy of thermodynamic properties calculation of this area and provide thermodynamic and dynamic support for marine environmental development and protection of Chinese offshore waters.