GEOTRACES Atlantic Section: Measurement of Helium Isotopes and Tritium

GEOTRACES 大西洋部分：氦同位素和氚的测量

• 批准号: 1132522
• 负责人: William Jenkins
• 金额: $ 1.77万
• 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: 2011
• 资助国家: 美国
• 起止时间: 2011-06-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1132522&HistoricalAwards=false
• 关键词: GEOTRACES; Atlantic; Section; Measurement; Helium

This Grant for Rapid Response Research (RAPID) will provide funding to a research team at the Woods Hole Oceanographic Institution to continue their collection of tritium and helium isotope samples on the interrupted GEOTRACES North Atlantic Zonal Section originally funded through an NSF ARRA award. Due to the mechanical failure of the research vessel KNORR's propulsion system, the original cruise was cut short about one third of the way through, and most of the scientific party was obliged to disembark in Cape Verde Islands. Extra effort is required to refurbish sampling vessels and re-stage the sampling effort for the second cruise set for October, 2011. The research team will make helium isotope and tritium measurements to provide useful biogeochemical rate information for the more centrally important TEI measurements made on the continuation of the first U.S. GEOTRACES global survey section. The primary contributions that tritium and 3He measurements can make to the program include: (1) Quantifying transit timescales and TEI dilution in the MOC: 3H and 3He are useful tracers for determining deep western boundary current tracer transport rates and interior mixing dilution scales, an important issue for many TEIs.(2) As a shallow water chronometer: using the tritium-3He clock, we can determine the time elapsed since fluid parcels have been subducted on timescales ranging from 6 months to several decades. We can also combine 3H - 3He ages and evolving 3H and 3He distributions with geostrophy, T,S, O2, nutrient, and TEI distributions to estimate transformation rates. (3) A TEI thermocline reflux gauge: 3He e is a unique ?nutrient-like? transient tracer that can be used as a so-called flux gauge to determine the rates at which thermocline-remineralized TEIs are returned to the upper ocean. This is important for biogeochemical models. (4) Gauging TEI hydrothermal dilution scales: Volcanic 3He injected during hydrothermal activity is a powerful conservative tracer of dilution in these plumes, allowing diagnosis of non-conservative behavior in some TEIs, and permitting flux estimates associated with hydrothermal activity on basin and global scale. The P.I. will be responsible for the acquisition, measurement, interpretation and modeling of the tritium and 3He to achieve the above objectives. Broader Impacts: The proposed work is in support of the GEOTRACES program, as such contributes to the broader societal goals and intellectual objectives espoused by that program. The primary issues related to this are pertinent to understanding the carbon cycle and predicting/mitigating climate change, as well as the marine food web and anthropogenic impacts on the oceans.

这项用于快速响应研究的赠款（Rapid）将为伍兹霍尔海洋学机构的研究团队提供资金，以继续收集其在最初通过NSF ARRA奖资金资助的北大西洋地区中断的北大西洋地区的trium和氦同位素样品。由于研究船Knorr的推进系统的机械故障，最初的巡航被缩短了大约三分之一的路程，大多数科学党都必须在Verde群岛上下船。需要额外的努力来翻新采样容器，并重新阶段为2011年10月的第二次巡航而进行采样努力。研究团队将进行氦同位素和tritium测量值，以提供有用的生物地球化学率信息，以实现对第一个美国Geotraces Global Global Speimention进行的更为重要的TEI测量。 Tritium和3HE测量可以对程序做出的主要贡献包括：（1）在MOC：3H和3HE中量化运输时间尺度和TEI稀释量是有用的示踪剂，可用于确定深层的西部边界当前边界当前的示踪速率和内部混合稀释度，并将其用于许多Teis的重要问题（2）供您使用Triioum。在6个月到几十年不等的时间尺度上已经对液体包裹进行了俯冲。我们还可以将3H -3HE年龄结合，并与地球植物，T，S，O2，营养和TEI分布相结合，以估算转换率。 （3）TEI热跃层回流量表：3He E是独特的吗？可以用作所谓的通量规来确定将热跃层隔离的TEI返回到上海的速率的瞬态示踪剂。这对于生物地球化学模型很重要。 （4）测量TEI热液稀释量表：在热液活性期间注入的火山3E是这些羽毛中稀释的强大保守示踪剂，可以诊断出某些TEI中的非保守行为，并允许与盆地和全球量表上的水热活动相关的通量估计。 P.I.将负责tritium和3he的获取，测量，解释和建模，以实现上述目标。更广泛的影响：拟议的工作是支持Geotraces计划的，因为这样的工作有助于该计划所支持的更广泛的社会目标和知识目标。与此有关的主要问题与了解碳周期并预测/缓解气候变化以及海洋食品网和人为对海洋的影响有关。