Numerical study of sea level and kuroshio volume transport change contributed by steric effect due to global warming

For direct consideration of seawater volume change by steric effect due to global warming, this study uses a MOM (Modular Ocean Model) version4 oceanic general circulation model, which does not use Boussinesq approximation. The model was improved to regional scale by increasing the grid resolution. Global simulation model results of CM2.1, HADCM3, MIROC3.2 provided by the IPCC AR4 (Intergovernmental Panel on Climate Change) were used as initial and boundary conditions, and SRES (Special Report on Emissions Scenarios) A1B was selected as a global warming scenario. The Northwestern Pacific region, which includes the Korean Peninsula, was selected as the study area, and the Yellow Sea which has a complex coastline, was expressed in detail by increasing grid resolution. By averaging the results of the three numerical experiments, we found that temperature & mean sea level(MSL) are increased by approximately 3℃/35cm from 2000 to 2100, respectively. Interestingly, The East Sea (Japan sea) appeared to show the largest change of MSL due to steric effect compared with Yellow and East China Sea. Numerical results showed that larger influence on East/Japan Sea is caused by the temperature and volume transport change in Tsushima Warm Current, which passes through the Korea Strait. A direct simulation of steric effect results in higher sea level rise compared with in-direct simulation of steric effect. Also, the Kuroshio Current, which is one of the major currents in the Northwestern Pacific, showed a decrease in transport as global warming progressed. Although there were differences between models, approximately 4~5SV of transport was reduced in 2100. However, there was no huge change in the transport of the Tsushima Warm Current.