Abstract This study examines temporal variations of 234Th-based particle export based on time-series observations conducted from 2004 to 2014 at the South-East Asian Time-series Study (SEATS) site in the basin area of the Northern South China Sea. It shows significant variability in particle export at both seasonal and interannual time scales. A significant feature of our data as observed by prior studies is that particle export was high during the NE monsoon in winter, but low during the inter-monsoon and SW monsoon. Particle flux increased with increasing mixed layer depth (MLD), primarily in winter due to the presence of a strong NE monsoon, in addition to influence by mesoscale features quantified by eddy kinetic energy values. Particle export was generally elevated when phytoplankton biomass was abundant, as shown by the significant correlation between particle fluxes and concentrations of chlorophyll (Chl) a and/or particulate organic carbon (POC) between 0 and 100 m. This is also supported by the negative correlation between 234Th residence time and Chl a concentration, suggesting that increased phytoplankton biomass accelerated downward particle sinking. The correlation disappeared however at Chl a values

中文翻译：

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物理和生物地球化学强迫对南海粒子输出的影响

摘要 本研究基于 2004 年至 2014 年在南海北部盆地区域的东南亚时间序列研究 (SEATS) 站点进行的时间序列观测，研究了基于 234Th 的粒子输出的时间变化。它显示了季节性和年际时间尺度上粒子输出的显着变化。先前研究观察到的我们数据的一个显着特征是冬季的东北季风期间粒子输出量很高，但在季风间和西南季风期间则很低。粒子通量随着混合层深度 (MLD) 的增加而增加，主要是在冬季，由于存在强烈的 NE 季风，此外还受到涡动能值量化的中尺度特征的影响。当浮游植物生物量丰富时，颗粒输出通常会增加，正如颗粒通量与叶绿素 (Chl) a 和/或颗粒有机碳 (POC) 浓度在 0 到 100 m 之间的显着相关性所示。这也得到了 234Th 停留时间和 Chl a 浓度之间的负相关性的支持，表明增加的浮游植物生物量加速了向下的颗粒下沉。然而，相关性在 Chl a 值处消失了