Abstract Phytoplankton size classes (PSC) is closely related to the export of surface carbon to the deep ocean, by affecting the phytoplankton photosynthetic efficiency, particle sinking rate, and the structure of the marine food chain .etc. As the largest marginal sea of the western North Pacific, there have been some researches of satellite-retrieved PSC algorithms and PSC-relative POC export in the South China Sea (SCS), however, long-term changes of PSC and its effect on POC export in the SCS are still poorly understood. In this study, we constructed a reliable long-time series PSC dataset in the SCS by evaluating the performances of published empirical PSC models. Our results revealed opposite changes of PSC on shelf and basin areas of the SCS in the past 16 yrs (2003-2018). Over the shelf regions, the proportion of phytoplankton in micro-size class (20-200 µm) raised significantly (0.28 unit·year-1, p

中文翻译：

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2003-2018年南海陆架和海盆区浮游植物大小等级变化相反

摘要 浮游植物大小等级（PSC）通过影响浮游植物光合效率、颗粒下沉率和海洋食物链结构等，与表层碳向深海的输出密切相关。作为北太平洋西部最大的边缘海，南海(SCS)卫星反演PSC算法和PSC相关POC输出已有一些研究，但PSC的长期变化及其对POC的影响SCS 中的出口仍然知之甚少。在这项研究中，我们通过评估已发表的经验 PSC 模型的性能，在 SCS 中构建了一个可靠的长期序列 PSC 数据集。我们的研究结果揭示了过去 16 年（2003-2018 年）南海陆架和盆地区域 PSC 的相反变化。在货架区域，