Dissolved organic carbon (DOC) cycle in the Yellow Sea and the East China Sea is dynamic due to high marine primary production, inputs of terrestrial organic matter through rivers and the atmosphere, and the resuspension of sedimentary organic matter. Radiocarbon (¹⁴C) is a useful tracer for studying the sources and cycle of marine DOC. However, it has rarely been used to investigate DOC cycle in this region. In this study, we measured the concentration and Δ¹⁴C values of DOC in the Yellow Sea and East China Sea in August 2020 and November 2021. We then synthesized these results with data from a previous study conducted in the East China Sea in February 2017. In this presentation, we will discuss the processes that regulate DOC cycle in the Yellow Sea and the East China Sea including the water mass mixing, seasonal variations, influence of pre-aged DOC sources from rivers, and the major source of DOC.

dissolved organic carbon,Radiocarbon Isotope