Neutrally-Buoyant Sediment Traps for Direct Sampling of the Upper Ocean Export Flux

摘要：了解海洋表层向海洋内部的颗粒输出通量是全球碳平衡的一个重要方面，因此对了解气候变化的动态具有重要意义。直到最近，表面通量已经通过表面系留浮动沉积物捕集器（STST）进行了研究，但这些捕集器一直受到其设计中固有人工因素的不确定性的困扰。该项目将测试一种通过中性浮力沉积物捕集器（NBST）测量表层通量的新方法，用于研究上层海洋的生物地球化学循环。待检验的假设是，直接采样上层海洋出口通量的最佳方法是使用随水平流自由漂移而保持特定深度的NBSTs。该计划是在马尾藻海的五次巡航中部署nbst，并测量第234个水柱的库存和相关的陷阱活动。

ABSTRACTOCE-9912044Understanding the export flux of particles from the surface ocean to the oceanic interior is an important aspect of the global carbon balance, and as such has great relevance to understanding the dynamics of climate change. Until recently, surface fluxes have been investigated by surface tethered floating sediment traps (STST), but these have been plagued by uncertainties in artifacts inherent in their design. This project will test a new approach to measuring surface flux by way of a neutrally buoyant sediment trap (NBST) for studies of biogeochemical cycling in the upper ocean. The hypothesis to be tested is that direct sampling of the upper ocean export flux can best be accomplished by the use of NBSTs that drift freely with horizontal currents while maintaining a specified depth. The plan is to deploy NBSTs on five cruises in the Sargasso Sea, and measure the 234Th water column inventory and associated trap activity.