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: 2148620
• 负责人: Jennifer Middleton
• 金额: $ 48.08万
• 依托单位: Columbia University
• 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=2148620&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.

国际地理计划计划的目标是了解痕量化学元件及其同位素在海洋中的分布。该项目将在两次即将到来的美国地理探险队进行南太平洋，南大洋和阿蒙森海的两次探险中进行贵重气体浓度，氦和氧同位素丰度的测量。贵族气体和同位素示踪剂将用于确定水热通风，冰川融化和海冰形成对该地区的水块的贡献。冰川熔体和海冰生产被认为是南极大陆架上痕量元素循环的重要驱动因素。这些过程还有助于确定南洋采源深水的特性。深水水热水的上升可能会给南大洋的地表水提供极限的微量营养素，从而提高了一级生产力。深层水热羽可能会导出通过Drake通道的水热痕量元素和同位素（TEIS）的通量。该项目将支持研究生，教师专业发展和公共宣传。在GEOTRACES GP17-OCE探险中，该团队将测量氦3，氦气浓度和霓虹灯浓度。在GP17-ANT探险中，他们将测量所有五种贵重气体的浓度，氦3，稳定的水的同位素组成和tri。具体目的包括（1）研究整个南太平洋水热输入的途径，（2），（2）量化其他水热的TEI通量和清除速率，（3）以量化雪和海冰的输入，与阿蒙森海中的铁和其他TEIS相关的冰层和其他TEIS相关，（4）从冰覆盖的边缘海到开放的南大洋。此外，由于有证据表明，并非所有向南海的热液输入都被发现，因此探险有可能扩大知识的知识，即对水柱的生物地球化学重要的其他水热系统的位置。这奖反映了NSF的法定任务，并通过使用基金会的智力效果和广泛的范围来评估支持，并通过评估值得评估。