Material transport patterns in the Bohai Sea: A Lagrangian flow network perspective

Lagrangian Flow Network (LFN) is a modeling framework that represents fluid transport among different oceanic regions as a network of interconnected nodes with directed and weighted links. This framework provides a powerful tool for studying transport and mixing phenomena in the ocean and offers unique advantages in analyzing the diffusion, transport pathways, and connectivity of materials. In this study, LFN is applied to construct a network representing material exchange between subdomains of the Bohai Sea (BS). Through the analysis of the network, various metrics such as vertex degree, betweenness, hydrodynamic communities, and clustering coefficients are obtained to unveil hidden transport patterns in the BS. The results indicate that high betweenness values signify a primary material transport path from Liaodong Bay along the left bank to the mouth of Bohai Bay, culminating at the Bohai Strait in the BS. Additionally, the study identifies eight hydrodynamic communities in summer and nine in winter using the Infomap algorithm. High clustering coefficients predominantly manifest in the center of a hydrodynamic community, suggesting material accumulation in those areas. Overall, this study demonstrates the applicability of the LFN framework in oceanic contexts and provides significant insights into understanding transport patterns within the Bohai Sea.