An improved method for evaluating the seasonal variability of total suspended sediment flux field in the Yellow and East China Seas

Abstract

The suspended sediment flux field in the Yellow and East China Seas (YECS) displays its seasonal variability. A new method is introduced in this paper to obtain the flux field via retrieval of ocean color remote sensing data, statistical analysis of historical suspended sediment concentration data, and numerical simulation of three-dimensional (3D) flow velocity. The components of the sediment flux field include (i) surface suspended sediment concentration inverted from ocean color remote sensing data; (ii) vertical distribution of suspended sediment concentration obtained by statistical analysis of historical observation data; and (iii) 3D flow field modeled by a numerical simulation. With the improved method, the 3D suspended sediment flux field in the YECS has been illustrated. By comparison with the suspended sediment flux field solely based on the numerical simulation of a suspended sediment transport model, the suspended sediment flux field obtained by the improved method is found to be more reliable. The 3D suspended sediment flux field from ocean colour remote sensing and in situ observation are more closer to the reality. Furthermore, by quantitatively analyzing the newly obtained suspended sediment flux field, the quantity of sediment erosion and deposition within the different regions can be evaluated. The sediment exchange between the Yellow Sea and the East China Sea can be evident. The mechanism of suspended sediment transport in the YECS can be better understood. In particular, it is suggested that the long-term transport of suspended sediment is controlled mainly by the circulation pattern, especially the current in winter.