Understanding regional sea level change under CO2-induced global warming in a Model for Interdisciplinary Research on Climate version 3.2(MIROC3.2)

Regional sea level changes resulting from CO2-induced climate changes have been investigated in a series of idealized experiments with medium-resolution version of MIROC3.2. Regional sea level change is not spatially uniform and the patterns are principally determined by density changes (baroclinic component) due to the surface fluxes of heat, freshwater and wind stress. Sea level change in barotropic circulation is shown in the Southern Ocean and it is mainly related by the wind stress. We also estimated baroclinic pressure change at each vertical level and decomposed the baroclinic response into the vertical modes of the ocean climatological stratification. The first baroclinic mode is responsible for about 80% of variance of the baroclinic response, and the second mode is responsible for about 10% of the variance, suggesting that the regional sea level change under global warming is determined by the displacement of ocean pycnocline. This research was supported by CREST, JST.