Dual Control of the Ocean Current and Terrestrial Inputs on GDGT-Based Sea Surface Temperature Reconstructions in the High-Deposition Marginal Sea

Understanding past climate variations is essential for predicting future climate scenarios. Glycerol dialkyl glycerol tetraethers (GDGTs) are valuable proxies for reconstructing past climates, yet their applicability in dynamic, high-deposition environments, such as continental marginal seas, remains uncertain. In this study, we analyzed GDGT distributions in 20 surface sediment samples collected along a longitudinal transect (121° 58' 48″ E) spanning different latitudes in the Southern Yellow Sea (SYS), China. Results indicate that terrestrial inputs, mainly transported by the Old Yellow River, significantly affect sea surface temperature (SST) reconstructions. SST variations in SYS are predominantly controlled by the Yellow Sea Warm Current (YSWC), with additional influences from the latitude and proximity to the coast. Our findings demonstrate that GDGT-based proxies provide reliable climate reconstructions even in marginal seas characterized by complex sedimentary environments and mixed organic matter sources.