Effect of waves on the dispersal of the Pearl River plume in winter

Waves, by enhancing surface wind stress and bottom stress, increasing water mixing, and creating water currents, play an important role in modifying the dispersal of river plumes. In this study, we used the COAWST modeling system to study the effects of waves on the dispersal of the Pearl River plume during winter. The waves help retain freshwater in the nearshore western shore and simultaneously displace the river plume further downstream in a down-wave direction. We distinguish the wave effects by analyzing their four components and the associated changes in freshwater transport. Among the four wave effects, the wave-induced enhancement of bottom stress is the most important process influencing the Pearl River plume along the western shore, followed by the enhancement of surface stress and the 3D wave forces. While for the mainstem of the estuary, enhancement of surface wind stress and bottom stress, the 3D wave forces are all important in altering the freshwater transport and saltier water intrusion.