Numerical modeling and theoretical analysis of the existence of the Pearl River plume bulge

Abstract

It is commonly believed that the bulge structure cannot be generated in the Pearl River region due to the trumpet-like estuary and the relatively wide mouth. However, the bulge structure was observed by Advanced Synthetic Aperture Radar (SAR). Then, the potential of the existence of the Pearl River plume bulge is proved by a theoretical framework applied with the Lantau channel parameters. The theoretical analysis suggests that the Lantau channel is one of principal influence factors of the bulge formation. This suggestion was carried out with a numerical model applying a theoretical framework using the Regional Ocean Modeling System (ROMS). Model results confirmed that an anticyclonic bulge was generated under southeasterly winds. The position of the simulated bulge is in accordance with that observed by SAR. The no-channel case run also proved that the Lantau channel, which serves as a water-road for the river water, can dramatically affect the bulge scale. In a word, this work aims at revealing the existence of the bulge structure in the Pearl River plume, which may require more observations and better understanding of the dynamic characteristics of the Pearl River plume bulge.