A numerical study on the circulation, wave and suspended sediment in the Yellow and East China Seas

Abstract

We summarize in this work a recent development of a SELFE-based three-dimensional numerical model for the Yellow and East China Seas (YSECS) equipped with multiple-scale circulation, wave and multiple-size suspended sediment modules. Some important improvements have been made. To deal with the multiple-scale circulation, we have introduced an open boundary condition to obtain stable solutions in the presence of multi-scale circulation. We have extended the non-cohesive sediment module of SELFE to the form applicable to mixture of cohesive and non-cohesive sedimentary regimes by implementing an extended form of erosional rate and a flocculation model for the determination of settling velocity of cohesive flocs. We assume that erosion of mixtures of cohesive (mud) and non-cohesive sediments (sand) is independent if clay content is below critical. Above critical clay content the bed behaves cohesively. In the non-cohesive regime exchange of sand and mud with bottom is independent, whereas in cohesive regime an erosion of mud and sand occurs simultaneously as cohesive sediment. The deposition is independent process for cohesive and non-cohesive sediments. Results of suspended sediment distributions in the Yellow Sea computed without wave and with wave have been compared with newly constructed GOCI images.mportant improvements have been made. To deal with the multiple-scale circulation, we have introduced an open boundary condition to obtain stable solutions in the presence of multi-scale circulation. We have extended the non-cohesive sediment module of SELFE to the form applicable to mixture of cohesive and non-cohesive sedimentary regimes by implementing an extended form of erosional rate and a flocculation model for the determination of settling velocity of cohesive flocs. We assume that erosion of mixtures of cohesive (mud) and non-cohesive sediments (sand) is independent if clay content is below critical. Above critical clay content the bed behaves cohesively. In the non-cohesive regime exchange of sand and mud with bottom is independent, whereas in cohesive regime an erosion of mud and sand occurs simultaneously as cohesive sediment. The deposition is independent process for cohesive and non-cohesive sediments. Results of suspended sediment distributions in the Yellow Sea computed without wave and with wave have been compared with newly constructed GOCI images.