Climatic Change Projection for the Ocean around Japan using a High-Resolution Coupled Atmosphere-Ocean Regional Climate Model

Abstract

We developed a high-resolution, Coupled Atmosphere-Ocean Regional Climate Model to project climate change over Japan with more sophisticated atmosphereocean interaction. The model represented sea surface temperature (SST) distribution well. An SST bias over the Japan Sea was improved by 10 to 20% compared to a non-coupled ocean model driven by atmospheric forcing in a GCM. These results indicate that realistic, high-resolution atmospheric conditions positively impact on the reproduction and projection of oceanic conditions.SST in the future projection simulation was 1 to 6°C warmer than in the present climate run. A particularly remarkable warming signal was projected to the sea east of Hokkaido in both summer and winter. The model also simulated cooling SST off Sanriku (143E/39N) in winter, which has never obtained by non-coupled ocean model. These projected SST results are likely to be related to future changes in surface wind.