In view of the importance of ocean component for representing climate change,efforts are underway to implement a high-resolution nesting model system in Model for Interdisciplinary Research on Climate(MIROC) for the North Pacific using the same ocean model as used in the coupled model MIROC5. By comparing double(10 km for the northwestern Pacific,50 km for the rest of the Pacific) and triple(double nesting plus 2 km resolution near Japan) nesting,it turns out that relative vorticity is drastically enhanced near Japan with 2 km resolution. It is hoped that such an elaborated nesting system will reveal detailed processes for the ocean heat uptake by,e.g.,intermediate water and mode water formation for which the“perturbed region”near Japan is the key region. In view of the importance of ocean component for posing climate change, efforts are underway to implement a high-resolution nesting model system in Model for Interdisciplinary Research on Climate (MIROC) for the North Pacific using the same ocean model as used in the coupled model By turns double (10 km for the northwestern Pacific, 50 km for the rest of the Pacific) and triple (double nesting plus 2 km resolution near Japan) nesting, it turns out that relative vorticity is drastically enhanced near Japan with 2 km resolution. It is hoped that such an an elaborated nesting system will reveal detailed processes for the ocean heat uptake by, eg, intermediate water and mode water formation for which the “perturbed region ” near Japan is the key region.