Paleo-temperature in the Yellow Sea during the mid-Holocene estimated using a numerical model

Mid-Holocene (MH, 6 ka BP or 6000 years before present) is one of the most important and widely studied periods of the Quaternary, for its climate is warmer than present day and has reference value for future climate prediction. Utilizing three-dimension hydrodynamic model POM (Princeton Ocean Model), we numerically reproduce water temperature distribution in the Yellow Sea (YS) during the MH winter and summer, with application of paleo-topography, which has significantly changed along the western coast compared to nowadays. It is found that the weaker winter monsoon during the MH generates both the warmer surface water in winter and weaker bottom cold watermass in summer. The shift of tidal front from MH to present, linked with evolution of YS bathymetry and coastline, has influence on the surface cold water pattern in summer. Additionally, the differences of heat gain in the YS between MH and modern time rely on the joint effects of surface heat flux and lateral heat flux differences. In the winter half year, surface heat flux difference dominates; while lateral heat flux difference is overwhelming in the summer half year.