Rapid, Autonomous Particle Flux Observations in the Oligotrophic Ocean

沉降到深海的颗粒在短时间内从海洋表面和与大气接触中去除生物过程所需的碳和必需的微量元素。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通量，而且这种方法既费时又费力。由于这些通量测量的时空尺度有限，很难确定控制颗粒有机碳（POC）命运的过程。伍兹霍尔海洋研究所的科学家们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上获得粒子通量观测结果。首先，将进行基于实验室的传感器校准实验，以确定系统的检测限并评估其对粒度的灵敏度。随后将进行实地工作，将从浮船获得的数据与从沉积物捕集器直接取样的数据进行比较。最后，该系统将在北大西洋部署大约一年，期间数据将通过卫星从生物地球化学浮标返回。今年的部署将是同类中首次收集几乎连续的、每小时分辨率的粒子通量代理测量数据。预计这些数据将对影响POC出口变异性的因素产生新的见解。该提案的一个潜在变革方面将是广泛应用一种新开发的方法，该方法可以在产生高分辨率数据的同时减少劳动力和运输成本。更广泛的影响：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该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研究员和少数民族研究员项目参与研究。

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.