The extension of the Changjiang River plume is one of the fundamental processes in the Yellow and East China Seas, which is responsible not only for the physical properties of seawater but also for the numerous physical, biogeochemical, and sedimentary processes in this region. The studies of the Changjiang River plume dated back to 1960s, followed by generations, and are still attracting numerous focuses nowadays. Here in this chapter, we will review the past studies on the Changjiang River plume and present some latest studies on this massive river plume. The latest research progresses on the Changjiang River plume are mainly related to the tidal modulation mechanisms. It is found that the tide shifts the Changjiang Rive plume to the northeast outside the river mouth, bifurcates the plume at the head of submarine canyon, and arrests the unreal up-shelf plume intrusion that occurred frequently in previous model studies. It is also found that the tidal residual current transports part of the Changjiang River plume to the Subei Coastal Water. These tidal modulation effects can answer the questions on the dynamics of Changjiang River plume that puzzled the research community for decades.
Part of the book: Coastal Environment, Disaster, and Infrastructure
An important hydrographic phenomenon in the Yellow Sea is the surface cold patches (SCP) in warm seasons, among which the most conspicuous are the Shandong SCP, Subei SCP, and Mokpo SCP. Previous studies based on monthly mean fields propose that these patches result from the collaboration of tidal mixing and tidal induced upwelling. While this is true for patches like the Shandong SCP, the monthly mean tidal mixing and upwelling alone cannot explain all their formations. In this study, through a detailed analysis of their patterns over a spring-neap tidal cycle, it is found that the Subei and Mokpo SCPs show distinct spring-neap variations. During the neap tide phase, strong stratification is established, and hence the cold patches in these two areas may be greatly weakened or even suppressed, while during the spring tide phase, the surface temperature reaches its minimum. That is to say, for these two SCPs, besides the well-accepted mechanisms, the effect of spring-neap tidal variation must be taken into account.
Part of the book: Coastal Environment, Disaster, and Infrastructure