MIYATA Hideaki The University of Tokyo, Graduate School of Engineering, Professor, 大学院工学系研究科, 教授 (70111474)
YAMAGUCHI Hajime The University of Tokyo, Graduate School of Engineering, Professor, 大学院工学系研究科, 教授 (20166622)
TABETA Shigeru The University of Tokyo, Graduate School of Frontier Sciences, Associate Professor, 大学院新領域創成科学研究科, 助教授 (40262406)
|Budget Amount *help
¥13,200,000 (Direct Cost: ¥13,200,000)
Fiscal Year 2006: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2005: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 2004: ¥5,100,000 (Direct Cost: ¥5,100,000)
CO2 was selected as diffusion substance in the sea, and the chemical reaction of CO2 and its impacts on marine biota were modeled in the fiscal year of 2004. Moreover, a full-3D (non-hydrostatic pressure approximation) ocean model was newly developed for mesoscale simulation. In addition, developed was a numerical code that overlaps a small-scale LES domain, which moves in a Lagrange way in this large-scale ocean model.
The code of LES for the oceanic turbulent flow of small-scale analysis by low-wavenumber forcing was developed in the fiscal year of 2005. Moreover, energy spectrum of velocity was analyzed from the time-series data measured at a few points in the real sea, and an analytical code was also developed for recovering spatial data from the time-series data. The result of the real-sea measurement was analyzed by using this. The real-sea observation was conducted 500km off Okinawa coast, where flow velocity, salinity, water temperature, and depth were measured for three days.
In the fiscal year of 2006, we succeeded in reproducing actual oceanic current flow in the sea area by forcing low-wavenumbers of flow energy in the large-scale ocean model. In addition, a case-study simulation was conducted by using the results of research items, such as the impact of CO2 on marine biota, the environmental assessment method of CO2, physical and chemical data collected from experiments under particular pressure and temperature, the behavior of CO2 droplets, CO2 dissolution in seawater. A comprehensive simulation was conducted on the condition that five small domains, which have the size of 37kmx1km, include six ships with different injection depth, and move in the mesoscale domain of 100km×300km, arranging models for the droplet rise speed and the dissolution rate. As a result, it was understood that pCO2 in a mesoscale domain can be lower than the no-effect concentration of CO2 for zooplankton.