Interannual variation in the distribution of Yangtze River-derived sediments in the Yellow Sea: Evidence from the suspended sediments.

The Yellow Sea is influenced by discharges from the Yangtze River, particularly during winter, when some Yangtze River sediments are transported into the Yellow Sea. These sediments affect the local marine ecosystem through contaminants and nutrients attached to fine-grained suspended sediments. However, the mechanisms controlling the spatial distribution of Yangtze River-derived sediments in the Yellow Sea are not fully understood. To address this, suspended sediment samples collected during the winters of 2010, 2011, and 2012 in the Yellow Sea were analyzed for grain size and mineral composition to determine the sediment provenance. These data were combined with hydrographic (seawater temperature, salinity, and density) and meteorological (winds) measurements to identify the factors influencing interannual variations in the spatial distribution of Yangtze River-derived sediments in the Yellow Sea. Dolomite spectral analysis of the suspended sediments revealed that certain stations were influenced by Yangtze River-derived sediments. The results demonstrated that the Yangtze River source exerted the strongest influence in 2010, followed by 2012, with the weakest influence observed in 2011. Although stronger winter winds in 2011 led to a broader distribution of the Yellow Sea Warm Current, the influence of Yangtze River-derived sediments was constrained by the low sediment load discharged into the sea. The distribution of Yangtze River-derived sediments in the Yellow Sea during winter is primarily controlled by the sediment load discharged from the Yangtze River into the sea during the summer of that year and secondarily by the strength of the winter monsoon. These findings are critical for understanding sediment dispersal systems, sea-land interactions, and source-sink processes in marginal seas under the dual pressures of increasing human activity and global climate change.