Rapid, Autonomous Particle Flux Observations in the Oligotrophic Ocean

沉淀到深海的颗粒从表层海洋中去除碳和生物过程所必需的微量元素，并在短时间内与大气接触。目前可用的技术只能在24小时到几天的时间尺度上解决这种流动，而且方法既费力又费时。鉴于这些通量测量的空间和时间尺度有限，很难确定控制颗粒有机碳(POC)命运的过程。来自伍兹霍尔海洋研究所的科学家将使用一种基于光学透射计的方法，从自主的生物地球化学剖面浮标获得颗粒物通量观测。首先，将进行基于实验室的传感器校准实验，以确定系统的检测下限，并评估其对颗粒大小的灵敏度。这之后将进行现场工作，将从浮标获得的数据与从沉积物捕集器获得的直接采样进行比较。最后，该系统将在北大西洋部署大约一年，在此期间，数据将通过卫星从生物地球化学浮标返回。今年的部署将是第一次收集几乎连续的、每小时分辨率的粒子通量代理测量。预计这些数据将为影响POC出口变异性的因素提供新的见解。这项提议的一个潜在的变革性方面是广泛应用一种新开发的方法，这种方法可以在生成高分辨率数据的同时削减劳动力和运输成本。广泛的影响：鉴于该系统的组件很容易在商业上获得，这意味着科学界的其他人有机会使用这项技术进行类似的测量。作为该项目的一部分，将支持和培训一名博士后。此外，本科生将通过伍兹霍尔海洋研究所暑期学生和少数民族研究员计划参与研究。

Particles settling to the deep ocean remove carbon and essential trace elements for biological processes from the surface ocean and contact with the atmosphere over short time scales. Currently available technology is only able to resolve this flux at timescales of 24 hours to a few days and the methods are both labor- and time-intensive. Given the limited spatial and temporal scale of these flux measurements, it has been difficult to determine the processes that control the fate of particulate organic carbon (POC). Scientists from Woods Hole Oceanographic Institution will use an optical, transmissometer-based method to obtain particle flux observations from autonomous, biogeochemical profiling floats. Initially, a laboratory-based sensor calibration experiment will be carried out to determine the detection limit of the system and evaluate its sensitivity to particle size. This will be followed by a field effort wherein data obtained from the floats will be compared against direct sampling from sediment traps. Lastly, the system will be deployed for about a year in the North Atlantic during which data will be returned via satellite from the biogeochemical float. This year long deployment will be the first of its kind to collect nearly-continuous, hourly-resolution proxy measurements of particle flux. The data is expected to yield new insights into the factors that influence variability in POC export. A potentially transformative aspect of this proposal will be the broad application of a newly developed method that cuts labor and ship costs while generating high resolution data.Broader Impacts: Given the components for this system are readily commercially available means others in the science community have the opportunity to use this technology to make similar measurements. One postdoc would be supported and trained as part of this project. In addition, undergraduate students will be involved in the research via the Woods Hole Oceanographic Institution Summer Student Fellow and Minority Fellow program.