Thermohaline Dynamics in the Northern Continental Slope of the South China Sea: A Case Study in the Qiongdongnan Slope

Abstract

Understanding the marine hydro-thermohaline environment is essential for terrestrial meteorology and the coastal ecosystem. Here, we provide insight into the hydro-thermohaline environment at the Qiongdongnan continental slope of the northern South China Sea and the mechanism controlling it, with focus on its short-term characteristics. We employ a well-validated three-dimensional unstructured-grid-based Finite Volume Coastal Ocean Model (FVCOM) to analyze the spatial-temporal behavior of its hydro-thermohaline structures and to quantify the transport fluxes over a full tidal period. The analysis reveals a two-layer flow structure with directionally oppositely moving layers in the along-isobaths direction. Furthermore, transport patterns undergo periodic changes. During the spring tide, the downslope (along-isobaths) transport of water/heat/salt is approximately 119%/70%/120% higher (62%/62%/62% lower) than during the neap tide. From analyzing the different terms in the thermohaline balance equation, we find that the main dynamic factors controlling heat transport over a tidal period are the gravitational convention and the mean flow, while the salt transport is only dominated by the mean flow. The data of the short-term thermohaline evolution of the QDNS provided in this study may be of use for future studies of the northern SCS, including its marine ecology and marine fisheries.

Geochemia iłów przejściowych kredy i trzeciorzędu (K/T) w południowo-wschodniej Turcji

“…The Ree patterns of the Lower Paleocene clays were relatively similar to those of the cratonic sandstones, while those of the Upper Cretaceous clays were entirely distinctive. The Al 2 O 3 /TiO 2 ratios and SiO 2 concentrations of the sedimentary rocks provided information about their origin (He et al 2010;Dai et al 2015). Al 2 O 3 /TiO 2 ratios in igneous rocks typically fall into three categories: felsic (21-70), intermediate (8-21), and mafic (3-8).…”