A numerical study with an eddy-resolving model to evaluate chronic impacts in CO2 ocean sequestration

To evaluate chronic impacts of CO2 ocean sequestration, we simulated the distribution of injected CO2 using an oceanic general circulation model (OGCM) with a horizontal resolution of 0.1°. The model can explicitly express transport and dispersion of dissolved CO2 by mesoscale eddies. The CO2 which is continuously injected by a moving ship dissolves and accumulates within the first several to 10 years, but the CO2 concentration has an upper limit after its initial increase as a result of the dilution effect of mesoscale eddies which counterbalances the accumulation effect of injection. We can estimate the CO2 injection flux with the CO2 maximum concentration below the “Predicted No Effect Concentration” (PNEC), an index to estimate concentration causing no effects on biota.