Abstract
The direct injection of CO_2 into the deep ocean is one of the feasible ways for the mitigation of the global warming. In the assessment process of it, the estimation of environmental impacts is strongly required, such as the change of CO_2 concentration and its spreading area. It is necessary to make CO_2 disperse as fast as possible and it is thought that injection with a pipe by a moving ship is effective for this purpose. To numerically investigate the time change of CO_2 concentration by turbulence diffusion in both small and meso-scales in the ocean, a moving and nesting grid technique was developed. To numerically generate a proper fluctuating flow field, a low-wavenumber forcing technique was adopted. The developed method was tested and validated by the numerical simulation of the ocean turbulent field. And, from the result of CO_2 dispersion simulation, it was found that the moving ship method reduces the biological impacts in a large extent, compared with fixed-point release.
