Collaborative Research: US GEOTRACES GP17-OCE and GP17-ANT: Properties and processes impacting other trace element and isotope cycles using noble gas and stable isotope tracers

合作研究：US GEOTRACES GP17-OCE 和 GP17-ANT：使用惰性气体和稳定同位素示踪剂影响其他微量元素和同位素循环的特性和过程

• 批准号: 2148473
• 负责人: Brice Loose
• 金额: $ 56.12万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148473&HistoricalAwards=false
• 关键词: Collaborative; Research; US; GEOTRACES; GP17

The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes in the oceans. This project will undertake measurements of noble gas concentrations, helium and oxygen isotope abundances, and tritium on two upcoming U.S. GEOTRACES expeditions to the South Pacific, Southern Ocean, and Amundsen Sea. The noble gas and isotope tracers will be used to determine the contributions of hydrothermal venting, glacial meltwater, and sea ice formation to the water masses of the region. Glacial melt and sea ice production are considered important drivers of trace element cycling on the Antarctic continental shelf. These processes also help establish the properties of Southern Ocean-sourced deep water. Upwelling of deep-sourced hydrothermal water could deliver limiting micronutrients such as iron to the surface waters of the Southern Ocean, driving enhanced primary productivity. Deeper-lying hydrothermal plumes may export fluxes of hydrothermal trace elements and isotopes (TEIs) through the Drake Passage. The project will support a graduate student, teacher professional development, and public outreach.During the GEOTRACES GP17-OCE expedition, the team will measure helium-3, helium concentration, and neon concentration. On the GP17-ANT expedition, they will measure the concentrations of all five noble gases, helium-3, the stable isotope composition of water, and tritium. Specific aims include (1) to study pathways for hydrothermal inputs throughout the South Pacific, (2) to quantify other hydrothermally-sourced TEI fluxes and scavenging rates, (3) to quantify the inputs of snow and sea ice melt in relation to iron and other TEIs in the Amundsen Sea, (4) trace the ice shelf pump mechanism in the Amundsen Sea, and examine the spread of northward spread of meltwater and TEIs from the ice-covered marginal seas to the open Southern Ocean. In addition, since there is evidence that not all the hydrothermal inputs to the Southern Ocean have been discovered, the expeditions have the potential to expand knowledge of where additional hydrothermal systems, important to the biogeochemistry of the water column, are located.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.

国际 GEOTRACES 计划的目标是了解海洋中微量化学元素及其同位素的分布。该项目将在即将进行的两次美国 GEOTRACES 南太平洋、南大洋和阿蒙森海探险中测量稀有气体浓度、氦和氧同位素丰度以及氚。稀有气体和同位素示踪剂将用于确定热液喷发、冰川融水和海冰形成对该地区水团的贡献。冰川融化和海冰产生被认为是南极大陆架微量元素循环的重要驱动因素。这些过程还有助于确定南大洋深水的特性。深层热水的上升可以将有限的微量营养素（例如铁）输送到南大洋的表层水域，从而提高初级生产力。更深的热液羽流可能会通过德雷克海峡输出热液微量元素和同位素（TEI）通量。该项目将支持研究生、教师的专业发展和公众宣传。在 GEOTRACES GP17-OCE 探险期间，该团队将测量氦 3、氦浓度和氖浓度。在 GP17-ANT 探险中，他们将测量所有五种稀有气体、氦 3、水的稳定同位素组成和氚的浓度。具体目标包括 (1) 研究整个南太平洋的热液输入路径，(2) 量化其他热液来源的 TEI 通量和清除率，(3) 量化与铁和水相关的雪和海冰融化的输入。阿蒙森海的其他TEI，（4）追踪阿蒙森海的冰架泵机制，并研究融水和TEI从冰盖边缘海向北扩散的情况。开放南大洋。此外，由于有证据表明并非所有进入南大洋的热液输入都已被发现，因此这些探险有可能扩大对其他热液系统所在位置的了解，这些系统对水体的生物地球化学非常重要。该奖项反映了通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。