The Luzon Strait Deep Overflow (LZDO) transports deep-water masses from the Pacific Ocean (upstream) to the South China Sea (SCS, downstream), playing a vital role in shaping the hydrographic and biogeochemical structure and regulating abyssal circulation within the SCS. Recent studies suggest that the seasonal variability of LZDO transport is primarily wind-driven; however, the specific mechanisms and key wind-forcing areas remain unclear. In this study, we use numerical model experiments to demonstrate that the seasonal variability of the LZDO is driven by wind stress both within the downstream SCS and upstream Pacific Ocean. This finding contrasts with previous views that considered the LZDO hydraulically controlled at the Luzon Strait sill and thus influenced solely by the upstream Pacific Ocean forcing. Additionally, we identify that the LZDO is particularly sensitive to wind forcing in specific North Pacific regions where geostrophic contours connect to the Luzon Strait due to topographic effects.

中文翻译：

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吕宋海峡深溢输运季节变率的上下游风应力强迫


吕宋海峡深溢流 （LZDO） 将深水块从太平洋（上游）输送到南海（南海，下游），在塑造南海水文和生物地球化学结构以及调节南海深海环流方面发挥着至关重要的作用。最近的研究表明，LZDO 运输的季节性变化主要是风驱动的;然而，具体机制和关键风力区域仍不清楚。在本研究中，我们使用数值模型实验来证明 LZDO 的季节性变化是由下游 SCS 和上游太平洋内的风应力驱动的。这一发现与以前的观点形成鲜明对比，这些观点认为 LZDO 在吕宋海峡基台上受到水力控制，因此仅受上游太平洋强迫的影响。此外，我们发现 LZDO 对特定北太平洋地区的风强迫特别敏感，由于地形效应，这些地区的地转等值线与吕宋海峡相连。