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

了解从海洋表面到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力学具有重要意义。直到最近，表面通量已经调查了表面系留的漂浮沉积物捕集器（STST），但这些一直困扰着固有的文物在其设计的不确定性。该项目将测试一种通过中性浮力沉积物捕获器（NBST）测量表面通量的新方法，用于研究上层海洋的生物地球化学循环。 要测试的假设是，上层海洋输出通量的直接采样可以最好地通过使用NBST来完成，NBST随水平流自由漂移，同时保持特定的深度。该计划是在马尾藻海的五次巡航中部署NBST，并测量234 Th水柱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.