Biogeochemical Responses to Nutrient Fluxes in the Open South China Sea: A 3‐D Modeling Study

Abstract

The South China Sea (SCS), one of the largest marginal seas in the world, is influenced by complex physical dynamics (such as seasonal monsoons, river discharge, mixing, upwelling, internal waves, and mesoscale eddies; e.g., Metzger, 2003). There is an energetic cyclonic gyre throughout the year in the northern SCS (NSCS), in contrast to the basin-scale cyclonic circulation during the winter but anticyclonic circulation during the summer in the southern SCS (K.-K. Liu et al., 2002). Intense phytoplankton blooms occur over the northern shelf of the SCS due to nutrient enrichments by the Pearl River discharge and the wind-driven coastal upwelling during the summer (e.g.,

The Effects of Atmospheric Nitrogen Deposition on the Marine Ecosystem of the Northern South China Sea

“…Chen, 2005; Wang et al., 2022). For the upper ∼50 m, the nutrient is depleted in summer (Du et al., 2017) due to biological assimilation, limited vertical nutrient supplies through the nutricline, and infrequent upwellings (Shuai et al., 2021). Given a low nutrient input from the deep water and continental shelves, AD‐N could be a vital source to impact the NSCS marine ecosystem significantly.…”

“…It is characterized by a shallower nutricline with a higher chlorophyll-a (Chl-a) concentration (∼0.3 mg m −3 ) in winter (Lu et al, 2015;Wang et al, 2021) and a deeper nutricline with a lower Chl-a concentration (∼0.1 mg m −3 ) in summer (Y.-L. Chen, 2005;Wang et al, 2022). For the upper ∼50 m, the nutrient is depleted in summer (Du et al, 2017) due to biological assimilation, limited vertical nutrient supplies through the nutricline, and infrequent upwellings (Shuai et al, 2021). Given a low nutrient input from the deep water and continental shelves, AD-N could be a vital source to impact the NSCS marine ecosystem significantly.…”

Framework to Extract Extreme Phytoplankton Bloom Events with Remote Sensing Datasets: A Case Study

“…For the more oligotrophic condition in the summer, picoplankton became dominant. In recent years, growing interest has been devoted to the LZB, mostly because of its complex controls and modulations by various dynamic factors such as the Kuroshio [9] and nonlinear subsurface upwelling [10]. These studies have reached a consensus that the primary driving force of LZB is the (seasonal) monsoon-induced winter mixed-layer deepening [5,6], while local circulations (including rotational mesoscale circulations, i.e., eddies) or the Ekman dynamics [11] provide the additional vertical nutrient inputs from the subsurface layers below the nutricline [12].…”