Change of marine ecosystem in the Japan Sea predicted by numerical experiments based on by global warming

To understand change of marine ecosystem induced by climate change in the Japan Sea, numerical experiments were performed using eddy-resolved ocean general circulation model (OGCM) and ecosystem model called NEMURO based on global warming. The model domain included whole of the JS with 4 shallow straits and its resolution was 1/12 degree. Numerical integrations were performed by OGCM from 2006 to 2100 using atmospheric conditions from the results of the MRI CGCM3 global climate model under the IPCC-AR5 rcp4.5, 6.0 and 8.5 scenarios, which was a member of CMIP5. As a result of global warming, temperature rising (2 -4 degrees Celsius) in photic layer and weakening of vertical convections were found in all experiments. The results of the ecosystem model were characterized by the following items: 1) Decreasing and downsizing of phytoplankton; 2) Weakening and early beginning of spring bloom (especially in the central Japan Basin). These characteristics were more remarkably found in rcp8.5 scenario.