Modelling the dispersal and depositional processes of the suspended sediment in the central South Yellow Sea during the winter

Abstract

AbstractThe muddy area in the centre of the South Yellow Sea (SYS) is formed and characterized by fine‐grained particles since the Yellow Sea circulation system became stable before 8000 years. The distribution and thickness of the central South Yellow Sea muddy area are both updated based on the interpretation of eight high‐resolution sub‐bottom profiles in central SYS, 2012. The area mainly locates within 34.5°–36.5°N, 122°–124.5°E, showing thick in the north and west and thin in the south and east with a ‘┌’ shape. The maximum thickness is up to 11 m. Meanwhile, there appears a weak deposition belt in the transition zone between the central South Yellow Sea muddy area and the slope deposit body surrounding Shandong Peninsula. In this paper, a numerical simulation under wind‐driven circulation in winter is established to study the dispersal and depositional processes of the suspended sediment. Studies show that the presence of a weak‐current‐low‐energy area by the tide is the primary factor to control the muddy area in central South Yellow Sea with similar results to previous research, but we find that the sediment is transported by the Yellow Sea Warm Current in winter. In winter, the Yellow Sea Warm Current can carry the southern sediment into here and we believe that it is the main driving force to transport sediment into the muddy area. The weak deposit band of the simulation result and measurement matched well; it is controlled by the shear front of the Yellow Sea Warm Current and the Yellow Sea Coastal Current. The shear front plays the role of a ‘water barrier’ to prevent the sediment carried by the Yellow Sea Coastal Current spreading directly to the muddy area and the sediment carried by the Yellow Sea Warm Current spreading to the coastal zone, so the weak deposit band arose. Copyright © 2016 John Wiley & Sons, Ltd.