Title of Project : Research on Advancement of Numerical Simulation of Oceanophysical Environment in Ocean Engineering

这组大学研究人员致力于开发大型海上浮式结构物（HFOS）对其周围海水海洋环境的海洋物理影响的数值模拟程序。本研究项目的主要目的是修改上述模拟程序，以便不仅可以同时评价一种高氟辛烷磺酸的海洋物理效应，而且可以同时评价其生物和化学效应；利用数值模拟方法预测了东京湾欧帕玛附近海域海水的温度、盐度、叶绿素a和溶解氧（DO），并与大型浮子结构附近的观测数据进行了比较。研究结果表明：(1)预测溶解氧的时变与观测溶解氧的时变有较好的一致性。(2)相反，叶绿素-a浓度预测值与观测值的吻合程度不理想。叶绿素-a浓度的建模需要显著改进。(3)为提高叶绿素-a的预测精度，应增加氮、磷等营养盐的测定，并检验营养盐的预测值与观测值是否一致。

This group of university researchers has engaged in developing numerical simulation program of predicting oceanophysical effects of a huge floating offshore structure (HFOS) to the marine environment of its surrounding sea water. The main aim of the present research project is to modify the above-stated simulation program so that not only oceanophysical effects but also biological and chemical effects of an HFOS might be evaluated simultaneously ; in addition to the sea water movement, water temperature and salinity, chlorophyll-a and dissolved oxygen (DO) in the sea water are predicted by numerical simulation, and compared with observation data measured in the close vicinity of Mega-Float structure moored off Oppama in Tokyo Bay.Some conclusion obtained in the present study are as follows :(1) Time-variation of predicted DO agrees fairly well with that of observed DO quantitatively.(2) To the contrary, the degree of agreement of predicted chlorophyll-a concentration with observed one is unsatisfactory. The modeling of chlorophyll-a concentration needs remarkable improvement.(3) In order to improve prediction accuracy of chlorophyll-a, additional measurement of nutritive salts such as nitrogen and phosphorus should be carried out, and agreement of nutritive salts between prediction and observation must be examined.