Recent warming of the Kuroshio Current has promoted offshore sediment transport in the Yellow Sea

Abstract

As cross-shelf gradients of most properties are typically much steeper than those in the alongshore direction, transport across isobaths tends to be inhibited, particularly at oceanic fronts where cross-shelf gradients are markedly pronounced. Consequently, variations in cross-shelf gradients may exert a significant influence on offshore transport; however, this influence is not yet well understood. This study employs reconstructed daily suspended sediment concentration (SSC) data from the Yellow Sea's offshore region to investigate the dynamics of offshore transport. Our analysis on an interannual scale shows that offshore SSC correlates more with temperature gradients at the oceanic front than with winter storms, despite the latter's vital role in causing frontal instability. The observed increase in offshore transport over the past two decades is likely connected to Kuroshio Current warming, which has strengthened the horizontal density gradient at the oceanic front, driving the strengthened offshore transport of coastal sediments during instability episodes.