Collaborative Research: Are all traps created equal? A multi-method assessment of the collection and detection of sinking particles in the ocean

有相当大的必要了解通过净初级生产将溶解的二氧化碳(CO2)固定为上层海洋中的有机物的生物和生态过程，以及随后将这些有机碳输送到海洋内部的过程。大部分流向深海的颗粒有机碳通量被认为是由下沉的颗粒所调节的。归根结底，是深层有机碳的运输和封存决定了海洋生物群对大气二氧化碳水平的影响，进而决定了气候的影响。目前，有各种方法可用来测量海洋中在特定时间段内下沉的颗粒物的数量，通常称为颗粒通量。不幸的是，所有这些方法都是相互独立使用的，几乎没有相互比较，这给哪种方法提供了最准确的估计留下了一些不确定性。这项研究寻求成为第一个标准化颗粒通量测量的协作性努力。为了使成本保持在最低水平，研究人员正在利用与英国科学家的合作，参加已经安排好的研究巡航。拟议的研究将比仅仅标准化颗粒通量测量产生更大的影响，因为它将使科学和模型界能够量化整个表层海洋的碳转移。此外，该项目还为学生提供了各种指导和培训机会。伍兹霍尔海洋研究所的一名博士生将获得他们的第一次航海经验，并将学习研究钍的同位素(第234)的所有处理步骤。斯基德莫尔学院将有一名本科生参与这项研究，巡航的结果也将成为本科生海洋学课程的优秀补充部分。来自伍兹霍尔海洋研究所和斯基德莫尔学院的研究人员将与南安普敦国家海洋学中心的一名科学家合作，对直接、示踪和光学传感器方法进行相互比较，以确定表层海洋中的下沉粒子通量。为此，他们将首先对两种类型的中性浮力陷阱和一种表面系留的漂流阵列进行比较。其次，将测量的捕集通量与从3D时间序列数据预测的第234次通量进行比较。最后，光学沉积物捕捉器的测量将与水柱和凝胶捕集器中的颗粒尺寸分布以及大容量泵过滤器上的颗粒分级进行比较。有了这项研究，全球海洋模型，特别是碳模型，将具有更高的准确性，并将能够从中得出更有力的结论。

There is considerable need to understand the biological and ecological processes that through net primary production fix dissolved carbon dioxide (CO2) into organic matter in the upper ocean, and the processes that subsequently transport this organic carbon in to the ocean's interior. Most of the particulate organic carbon flux to the deep ocean is thought to be mediated by sinking particles. Ultimately it is the deep organic carbon transport and its sequestration that define the impact of ocean biota on atmospheric CO2 levels and hence climate. Currently, various methods are available to measure the amount of particles in the ocean that sink over a specified period of time commonly referred to as particle flux. Unfortunately, all of these methods are used independently of each other with very little intercomparison, leaving some uncertainty as to which approach provides the most accurate estimates. This study seeks to be the first concerted effort to standardize particle flux measurements. Seeking to keep the cost modest, the researchers are taking advantage of a collaboration with scientists in the United Kingdom to participate in an already scheduled research cruise. The proposed research will have much greater impact that merely standardization of particle flux measurements because it will provide the science and modeling community the ability to quantify the transfer of carbon throughout the surface ocean. Also, this project provides a variety of mentoring and training opportunities for students. A PhD student at Woods Hole Oceanographic Institute will get their first sea-going experience and will learn all of the processing steps for the study of an isotope of thorium (234Th). Skidmore College will have an undergraduate participant in the research and the results from the cruise will also be an excellent additional component for undergraduate oceanography classes.Researchers from Woods Hole Oceanographic Institution and Skidmore College, in collaboration with a scientist from the National Oceanography Centre, Southampton will inter-compare direct, tracer, and optical-sensor methods used to determine sinking particle fluxes in the surface ocean. To do this, they will firstly conduct a comparison of two types of neutrally buoyant traps and one surface-tethered, drifting array. Secondly, measured trap fluxes will be compared to predicted 234Th fluxes from a 3D time-series of data. Lastly, optical sediment trap measurements will be compared to particle size distributions in the water column and gel traps, as well as size-fractionated particles on filters from large volume pumps. With this research, global ocean models, particularly carbon, will have greater accuracy and stronger conclusions will be able to be drawn from them.