A regional ocean general circulation model with different parameterizations of subgrid mesoscale mixing is used to study the evolution of sequestered CO2 in the North Pacific after it has been validated for the annual uptake of chlorofluorocarbons (CFCs). The forcing of annual mean wind stress and perpetual wintertime (March) climatology is used to obtain the steady state flow fields, which are used to advect the sequestered CO2, Most model runs are conducted under the assumption of no exchange of CO2 between the atmosphere and the ocean. The simulated results show that the discharge depth is important for isolating sequestered CO2 from venting to the atmosphere. It can be demonstrated that the depth of over 1000 m may be necessary for the storage of CO2 in the ocean over a few hundred years. In terms of the coupled model of the atmosphere and the model ocean, after 50 years continuous injection, the escape rate from the ocean to the atmosphere is more than 10% of the injection rate. The different flow fields affect the distribution of sequestered CO2, which is also discussed in terms of different parameterizations of mixing of tracers.