Modelling the winter Sargassum blooms in the Yellow Sea: considering wind, current and growth

Winter golden tides caused by Sargassum horneri are becoming recurrent events in the Yellow Sea. However, their sources and formation mechanisms remain unclear. By integrating a particle tracking model with a growth model of S. horneri, the roles of two probable sources in the formation of a winter golden tide in 2016 were investigated. The optimal windage coefficient for floating S. horneri was 0.4 %. Particle tracking experiments indicated that S. horneri released from Shandong Peninsula in October could reproduce the satellite-observed golden tide. The recorded temperature and nutrient concentrations along the particle trajectories were enough to support the formation of a large-scale golden tide. These findings support the speculation that Shandong Peninsula was the probable source of winter golden tides in the Yellow Sea. However, considering the absence of benthic population around Shandong Peninsula, it might serve as a “rest stop” for the floating S. horneri from a local population, Liaodong Peninsula or other unknown sources. The findings of this study have important implications for monitoring and model improvement. Other sources along the coasts of China and the Korean Peninsula need to be explored, and the interannual variability of golden tides should be investigated in the future.