Testing methods for direct measurement of particle settling velocities and fluxes in the sea

沉积物捕集器被广泛用于定量物质的垂直通量和收集下沉颗粒有机物(POM)以进行化学分析。它们提供了通过水柱的POM的空间、阶段性、季节性和年际通量的证据，将地表水过程的可变性与海洋内部和海底的通量联系起来，并表明强烈的再矿化和改变影响了水柱中的POM。在这个项目中，纽约州立大学石溪分校的研究人员将对最近作为MedFlux计划的一部分开发的沉降速度捕集器进行修改，在旋转的球阀上方和下方安装摄像头，以监控落入捕集器和球旋转后的颗粒沉降速率。这些测量应该使他们能够明确地确定颗粒是否在球上结合以产生人为高的沉降速度，或者之前的沉降速度估计是否真的很坚固。更广泛的影响：沉降速度陷阱的测试和开发将理想地允许颗粒沉降速率的现场测量，这反过来又对水柱内的元素循环提供关键的约束。收集的样本还将有助于评估各种压载材料(例如碳酸盐、蛋白石等)的相对重要性。虽然捕集器的发展对我们理解生物泵很重要，但更好地了解碳通量的能力也对更大的社会问题有直接影响，例如海洋和大气中的二氧化碳浓度。

Sediment traps are widely used to quantify vertical fluxes of material and to collect sinking particulate organic matter (POM) for chemical analyses. They have provided proof of spatial, episodic, seasonal, and interannual fluxes of POM through the water column, have linked variability in surface water processes to fluxes in the interior of the ocean and to the sea floor, and have shown that intense remineralization and alteration affects POM in the water column. In this project, researchers at the State University of New York at Stony Brook will modify a settling velocity trap developed recently as part of the MedFlux Program by installing cameras above and below the rotating ball valve to monitor particle settling rates as they fall into the trap and after the ball rotation. These measurements should allow them to unequivocally determine whether particles are combining on the ball to produce artificially-high settling velocities, or if the previous settling velocity estimates are truly robust.Broader Impacts: Testing and development of the settling velocity traps will ideally allow for in situ measurements of particle settling rates that in turn provide critical constraints on elemental cycling within the water column. Collected samples will also allow assessment of the relative importance of various ballast materials (e.g., carbonate, opal, etc.). While the trap development is important to our understanding of the biological pump, the ability to better understand carbon fluxes also has a direct impact on larger societal issues such as CO2 concentrations in both the oceans and the atmosphere.