We measured particulate organic carbon (POC) fluxes from the euphotic zone into the twilight zone and deep waters (>1000 m) that occurred between the shelf and the basin in the South China Sea (SCS) and at the SouthEast Asia Time Series Station (SEATS) using floating sediment trap arrays. Additionally, selected sinking particles were imaged by scanning electron microscope (SEM) to reveal particle morphology and composition. Results showed large variations in POC fluxes with elevated values (32–104 mg-C m−2 d−1) below the euphotic zone and a trend towards lower values in the deep SCS. Vertical POC fluxes measured in deep waters between the shelf and the SCS basin were much higher than those estimated by Martin’s attenuation equation. These elevated POC fluxes in deep waters were attributed to lateral particle transport as opposed to enhanced settling out of the euphotic zone. SEM images of sinking particles at 150 m show abundant marine biogenic detritus, while those in deep waters contained a higher proportion of lithogenic material. A great deal of the spatial variability in POC fluxes across the twilight zone and deep waters of the SCS cannot be represented by current biogeochemical models.
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机译：我们测量了发生在南海大陆架和盆地之间以及东南亚时间序列站之间的，从富营养区进入暮光区和深水区（> 1000 m）的颗粒有机碳（POC）通量（ （SEATS）使用浮动沉积物捕集阱阵列。此外，通过扫描电子显微镜（SEM）对选定的沉没颗粒成像，以揭示颗粒的形态和组成。结果表明，在富营养区以下，POC通量有较大的变化（32–104 mg-C m −2 d −1 ），并且在低浓度区呈较低的趋势。深度SCS。在架子和南海盆地之间的深水中测得的垂直POC通量要比马丁衰减方程所估计的要高得多。这些深水中POC通量的升高归因于横向颗粒传输，而不是增加了从富营养区的沉降。沉积在150μm的颗粒的SEM图像显示了丰富的海洋生物碎屑，而深水中的颗粒含有更高比例的成岩物质。目前的生物地球化学模型不能代表跨越南海暮光带和深水的POC通量的大量空间变异性。
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