Autonomous Ocean Carbon Observer Development and Calibration

海洋生物碳泵（OBCP）在全球碳循环和大气二氧化碳浓度中起着重要作用。光合生物的燃料的OCBP生活和死亡的一个星期到一个星期的基础上，和由此产生的下沉（或输出）的有机和无机碳颗粒从表层和这些颗粒在较深的沃茨的消耗损失是类似的变量。简单地说，由于依赖于短期、季节性和空间有限的船舶观测，对OCBP的了解很少;因此，对其强度和未来轨迹的模型估计具有很大的不确定性。为了解决这一差距，研究人员将设计和海上测试两个机器人拉格朗日海洋碳观测器（OCO）浮子，能够执行8个月至多年的任务，但能够在每小时至每日的时间尺度上解决通量过程，并通过卫星遥测在海洋的任何地方运行时以真实的时间中继数据。OCO的开发使得能够识别特定的路径和控制颗粒有机和无机碳（POC和PIC）从表层海洋到次表层沃茨的垂直转移。该项目逻辑上是从研究人员的开发和成功部署的机器人拉格朗日碳探测器（CE）和碳通量探测器（CFE）浮子，光学测量POC和PIC浓度和通量变化到1000米的深度。CFE的一个独特能力是它能够测量不同尺寸和类别的颗粒所携带的碳的沉降通量。该项目将合并CFE和CE功能以创建OCO。该团队将通过在项目的所有阶段（开发，实验室，航海和解释）和教室中让加州大学伯克利分校的本科生和一名研究生参与，为STEM劳动力的发展做出贡献。具体而言，CFEs和两个新的海洋碳观测器（OCO）将于2023年1月在海上建造和测试部署，同时测量粒子通量和浓度分布。在这些自主仪器在上千米内的目标深度漂移的时间期间（被传送到表面进行定位和真实的时间双向遥测所中断），它们将自主地量化捕获的下沉物质的固有光学特性和尺寸分布。Bishop等人（2016; Biogeosciences 13，3019-3129，doi：10.5194/bg-13-3109）描述了CFE的功能和方法，用于将原始OSR图像渲染为严格定义的粒子负载固有光学测量-衰减和交叉偏振光子产率。Bourne等人（2019; Biogeosciences，16，1249-1264; doi：10.5194/bg-16-1249-2019）表明，衰减与在150 m处通过配备采样器的CFE“（CFE-Cal浮子）”在广泛的颗粒通量和粒度分布范围内采样的POC和PN密切相关（r^2 0.86）。计划进一步部署CFE-Cal浮标，对至少500 m深度的下沉材料进行采样，这将使我们对衰减代理的校准得到验证，并使PIC光通量代理的首次校准成为可能。Bourne等人（2021; Biogeosciences，18，3053-3086，doi：10.5194/bg-18-3053-2021）证明了CFE解析和量化中层不同粒径类别所携带的垂直通量的独特能力;此外，他们描述了原型算法，该算法将导致CFE上真实的通量尺寸分布分析。该项目将使CFE和OCO系统能够在全球海洋中完全自主地长期部署。商业彩车供应商（MRV Systems）和传感器制造商（Seabird Scientific）的参与可能会为OCO带来商业化途径。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The very fast and dynamic ocean biological carbon pump (OBCP) plays a fundamental role in the global carbon cycle and in setting concentrations of atmospheric carbon dioxide. Photosynthetic organisms that that fuel the OCBP live and die on a week to week basis, and the resulting sinking (or export) of organic and inorganic carbon particles from the surface layer and consumption losses of these particles in deeper waters are similarly variable. Simply stated, the OCBP is poorly understood due to dependence on short- term, and seasonally and spatially limited ship observations; thus model estimates of its strength and future trajectory are highly uncertain. To address this gap, the investigators will engineer and sea-test two robotic Lagrangian Ocean Carbon Observer (OCO) floats capable of 8 month to multi-year missions, yet able to resolve flux processes on hourly to daily time scales and relay data in real time via satellite telemetry while operating anywhere in the ocean. The development of the OCO enables the identification of specific pathways and controls on the vertical transfer of particulate organic and inorganic carbon (POC and PIC) from the surface ocean to subsurface waters. The project logically follows on from the investigator’s development and successful deployment of robotic Lagrangian Carbon Explorer (CE) and Carbon Flux Explorer (CFE) floats, which measure optically POC and PIC concentration and flux variability to depths of 1000 m. A unique capability of the CFE is that it is able to measure the sinking flux of carbon carried by different sizes and classes of particles. The project will merge CFE and CE capabilities to create the OCO. The team will contribute to the development of a STEM workforce by engaging UC Berkeley undergraduates and one graduate student in all phases (development, laboratory, seagoing, and interpretive) of the project and in the class room. Specifically, CFEs and two new Ocean Carbon Observers (OCOs) that simultaneously measure both particle flux and concentration profiles will be constructed and test-deployed at sea in January 2023. During the times that these autonomous instruments drift at target depths within the upper kilometer (interrupted by transit to the surface for location and real time bidirectional telemetry), they will autonomously quantify the inherent optical properties and size distributions of sinking material captured. Bishop et al. (2016; Biogeosciences 13, 3019-3129, doi:10.5194/bg-13-3109) describe CFE capabilities and methodology for rendering raw OSR imagery to rigorously defined inherent optical measures of particle loading -- attenuance and cross-polarized photon yield. Bourne et al. (2019; Biogeosciences, 16, 1249-1264; doi:10.5194/bg-16-1249-2019) show that attenuance is strongly correlated (r^2 0.86) with POC and PN sampled at 150 m by sampler-equipped CFEs “(CFE-Cal floats)” over a broad range of particle flux and particle size distributions. Planned further deployment of the CFE-Cal floats to sample sinking material to depths of at least 500 m will enable validation of our calibration of the attenuance proxy and to enable a first calibration of the PIC optical flux proxy. Bourne et al. (2021; Biogeosciences, 18, 3053–3086, doi:10.5194/bg-18-3053-2021) demonstrate the unique capability of CFEs to resolve and quantify the vertical flux carried by different particle size classes in the mesopelagic; furthermore, they describe prototype algorithms that will lead to flux size-distribution analysis in real time on the CFEs. The project will enable fully autonomous long-term deployments of CFE and OCO systems in the global ocean. The involvement a commercial float vendor (MRV Systems) and sensor manufacturer (Seabird Scientific) may lead to a commercialization pathway for the OCO.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.