Collaborative Research: Development of a Submersible, Autonomous Rn-222 Survey System

合作研究：开发潜水式自主 Rn-222 测量系统

• 批准号: 1028990
• 负责人: John Breier
• 金额: $ 69.64万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1028990&HistoricalAwards=false
• 关键词: Collaborative; Research; Development; Submersible; Autonomous

The PI's request funding to develop a submersible system capable of in situ 222Rn analysis while deployed from a remotely-operated vehicle (ROV) or autonomous underwater vehicle (AUV). Such a system would allow researchers to conduct high-resolution radon surveying through 3-D grids of bottom water and later return to sites of interest to measure a 222Rn time-series in order to quantify SGD fluxes. The system design relies on a new technique to sparge radon, while submerged, from the water for analysis via bubbling a closed air loop through a contained water column. Preliminary evidence shows this to be a viable approach. Submarine groundwater discharge (SGD) is quickly gaining recognition as an important delivery mechanism of new and recycled nutrients to the coastal ocean. Chemical tracers such as 222Rn and radium isotopes offer excellent utility at detecting groundwater discharge zones and quantifying associated fluxes in nearshore (shallow) waters, but the traditional approaches to sampling and measuring these tracers become progressively less useful as the water column deepens, stratification strengthens, and physical mixing becomes more complex. In deeper waters (1) of the continental shelf where outcropping geological units can focus SGD, and (2) around critical habitats like coral reef ecosystems, one?s ability to measure these tracers is limited to grab sampling-scale resolution. Such resolution is generally not sufficient to understand the pathways, driving forces, and rates of these discharges, nor is it conducive to quantifying associated nutrient delivery fluxes. Prior to assessing the global significance of SGD, then, there exists great need for a tool capable of in situ, continuous measurement of geochemical tracers of SGD in deeper waters of the continental shelf.Broader Impacts: Since this proposed study develops a new research tool available for other scientists, the success of this study will have a large and broad impact on SGD studies in important deep basins, hydrothermal studies quantifying hydrothermal flow, and deep-water circulation and mixing studies using Rn-222 as a tracer. The investigators have included a plan for outreach to sponsor a two-semester, senior Design Clinic team of 3-4 undergraduate female engineering students from Smith College's Picker Engineering Program. This undergraduate team will gain experience working on a real-world engineering problem and this project will likewise benefit from their engineering contribution. Breier has undertaken a similar collaboration with Smith College for the NDSF microbial mat sampler project and the results to both sides have been outstanding. Breier and Singh will also mentor a MIT/WHOI Joint Program Ph.D. student as part of this project, with the hope that one of the Smith College engineering students may make this transition. Peterson will also serve as an undergraduate mentor.

PI 请求资助开发一种潜水系统，该系统能够在远程操作潜水器 (ROV) 或自主水下航行器 (AUV) 上部署时进行原位 222Rn 分析。这样的系统将允许研究人员通过底层水的 3D 网格进行高分辨率氡气测量，然后返回感兴趣的地点测量 222Rn 时间序列，以量化 SGD 通量。该系统设计依赖于一种新技术，通过在封闭的水柱中鼓泡闭合空气回路，在浸没时从水中喷出氡气进行分析。初步证据表明这是一种可行的方法。海底地下水排放（SGD）作为向沿海海洋输送新的和回收的营养物质的重要输送机制而迅速得到认可。 222Rn 和镭同位素等化学示踪剂在检测地下水排放区和量化近岸（浅水）水域的相关通量方面具有出色的实用性，但随着水柱加深、分层加强、传统的采样和测量这些示踪剂的方法变得越来越不那么有用。并且物理混合变得更加复杂。在 (1) 大陆架更深的水域中，露头的地质单元可以集中 SGD，以及 (2) 在珊瑚礁生态系统等关键栖息地周围，测量这些示踪剂的能力仅限于获取采样规模分辨率。这种分辨率通常不足以了解这些排放的路径、驱动力和速率，也无利于量化相关的养分输送通量。因此，在评估 SGD 的全球重要性之前，非常需要一种能够在大陆架更深水域中原位连续测量 SGD 地球化学示踪剂的工具。 更广泛的影响：由于这项拟议的研究开发了一种新的研究工具这项研究的成功将对重要深盆地的 SGD 研究、量化热液流的热液研究以及使用 Rn-222 作为深水循环和混合研究产生巨大而广泛的影响，可供其他科学家使用。示踪剂。研究人员制定了一项外展计划，赞助一个为期两个学期的高级设计诊所团队，该团队由来自史密斯学院皮克工程项目的 3-4 名工程女本科生组成。这个本科团队将获得解决现实世界工程问题的经验，该项目同样将从他们的工程贡献中受益。 Breier 与史密斯学院就 NDSF 微生物垫采样器项目进行了类似的合作，双方的成果都很出色。 Breier 和 Singh 还将指导 MIT/WHOI 联合项目博士生。作为该项目的一部分，希望史密斯学院的一名工程系学生能够实现这一转变。彼得森还将担任本科生导师。