Effects of Regional Coupled Climate Modelling on Future Climate Projection for the Western North Pacific

Abstract

This study presents preliminary results of a regional coupled climate model (RCCM) applied to future climate change projection for the western North Pacific. The RCCM consists of the Regional Ocean Modeling System (ROMS) as an oceanic component and the Weather Research Forecast (WRF) as an atmospheric component. The ocean model has a horizontal resolution of 1/12 degrees while the atmospheric model, covering the East Asian region, has a horizontal resolution of 50 km. As the initial and lateral boundary conditions we used future climate changes under Representative Concentration Pathway 4.5 scenario simulated by CanESM2 that well reproduces the East Asian monsoon. We will present regional patterns in future changes compared with global model projections including the changes in Kuroshio-Oyashio extension region and highlight the two-way coupling effects of regional ocean and atmosphere models in our RCCM projections focusing on inter-annual variability. It is notable that the projected changes by the RCCM showed a considerable difference from the projected changes by its ocean component (ROMS) only with atmospheric forcing from the global model CanESM2.nent and the Weather Research Forecast (WRF) as an atmospheric component. The ocean model has a horizontal resolution of 1/12 degrees while the atmospheric model, covering the East Asian region, has a horizontal resolution of 50 km. As the initial and lateral boundary conditions we used future climate changes under Representative Concentration Pathway 4.5 scenario simulated by CanESM2 that well reproduces the East Asian monsoon. We will present regional patterns in future changes compared with global model projections including the changes in Kuroshio-Oyashio extension region and highlight the two-way coupling effects of regional ocean and atmosphere models in our RCCM projections focusing on inter-annual variability. It is notable that the projected changes by the RCCM showed a considerable difference from the projected changes by its ocean component (ROMS) only with atmospheric forcing from the global model CanESM2.