Themes

Predicting the Marine Environment Change, and Grasping Its Mechanism

To approach with numerical models is essential for grasping the mechanism of marine environment change and predicting the one in the future. We have suggested that the simulation driven by real external changing forces is important in discussing environment change with models. Especially, we have considered the reproducibility of the model for coastal zone phenomena and improved its accuracy.(Literature.2)

Megafloat


Also we developed Multi-Scale Ocean Analysis Model by combining the hydrostatic approximation model and the non-hydrostatic approximation model with multi-stage Nested-grid for the purpose of analyzing multi-scaled phenomena in the ocean simultaneously.
With this model, we can do relatively accurate calculation of the wide-area flow field with low computation load including the sectional flow field in such areas that the hydrostatic approximation is not available(ex. around the stracture). This model is expected to be applied for a broad range of Science and Engineering(ex. Evaluation of the technology to promote vertical mixing for improving and controlling the environment, Analysis of the natural phenomenon involving the strong convection flow by the effect of complicated terrain or the buoyancy(Literature.3).

Evaluating the Impacts on Marine Environment Caused by Human Activities or Artificial Structures

Our approaches to these kinds of evaluation are based on the simulation by the numerical models as well as on-site investigation.

Megafloat


For example, we have worked on the prediction of the impact on coastal marine environment caused by the super-huge floating structure proposed as a innovative way to utilize the marine space. In this research, we did some field studies such as Mega-float experiment in Tokyo Bay and the numerical simulation using the ecosystem model. Finally, we proved that the water pollution caused by some creatures' activities clinging to the structure's surface and the infuluence on the seabed environment by such creatures' falling onto the bottom is critical. At the same time, we evaluated the impact on the marine environment from a perspective of the material cycle.(Literature.1)

Using the Newer Method of Higher level...

Using the open sea and coastal zone combining model, the data assimilation with the remote-sensing observations ,and the evaluation of the tidal exchange by real-time simulation, we are researching the cross-ineteraction of open sea and coastal zone, the contribution of the event phenomena to material cycle and so on.

Literature

  • [1] 北澤大輔, 藤野正隆, 多部田茂, 超大型浮体式構造物の海洋生態系への影響に関する研究, 日本造船学会論文集, Vol.192, pp.277-287, 2002.
  • [2] S. Tabeta and M. Fujino, Comparison between simulation results and field data about currents and density in Tokyo Bay, Journal of Marine Science and Technology, Vol.1, pp.94-104, 1996.
  • [3] T. Kinoshita, S. Tabeta, M. Fujino, Numerical simulation of artificial purification system by using hydrostatic and FULL-3D combined model, 22nd International Conference on Offshore Mechanics and Arctic Engineering, 2003.