EAGER: Constraining the Y-axis: Towards Quantitative Constraints for Precipitation and Temperature Using Speleothem Isotope and Trace Element Data

EAGER：约束 Y 轴：使用 Speleothem 同位素和痕量元素数据对降水和温度进行定量约束

• 批准号: 1935490
• 负责人: Yemane Asmerom
• 金额: $ 8.15万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1935490&HistoricalAwards=false
• 关键词: EAGER; Constraining; axis; Towards; Quantitative

This project uses funds, under the auspices of the EArly Concept Grant For Exploratory Research (EAGER) program, to focus on ways to take advantage of recent advances in mass spectrometry and data analysis in order to produce quantitative measures of temperature and precipitation from the paleoclimate record.An initial analytical finding suggests that the 88Strontium/86Strontium ratio in carbonates is sensitive to changes in temperature. This ideal relationship has been found to be complicated by limited experimental data that suggest that other factors, such as growth kinetics may play a role in this value. The researcher made some initial measurements using high temperature and low temperature carbonates and the data are encouraging to the extent that there seems to be a strong relationship between 88Strontium/86Strontium and temperature. There is no data on hand, however, to convincingly demonstrate temperature dependence in the range of temperature relevant for paleoclimate. Recent advances in thermal ionization mass spectrometry (TIMS) coupled with the "double spike" method could allow enough accuracy and precision to test the idea. In addition, stalagmites from Fort Stanton Cave that grew through the full climate swings that took place from the Last Glacial to the Early Holocene are ideal for analysis and are in-hand. The Strontium isotopic work will be attempted in a laboratory that houses a new generation of amplifier that would make it possible to obtain very accurate and precise 88Strontium/86Strontium ratios, sufficient to resolve potential changes in temperature at a scale relevant for paleoclimate. The researcher will also work on the design of a sample chamber that can accommodate long stalagmite samples.Another aspect of the project that holds promise is the combined technical achievements in high-throughput and high-quality elemental data using newer excimer lasers coupled to inductively coupled plasma mass spectrometry (ICP-MS) instruments and new ways to look at data using machine learning. Initial results by the researcher show that some trace elements, especially alkali and alkali-earth elements, may coherently vary with stable isotopes, thus providing the multidimensional data needed for machine learning applications. The activities are scientifically important and fit well into the potentially transformative, high-risk but potential high payoff research attributes of the EAGER program.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.

该项目利用EARLY探索性研究概念基金（EAGER）项目资助的资金，重点研究如何利用质谱和数据分析的最新进展，从古气候记录中定量测量温度和降水量。初步分析结果表明，碳酸盐中的88锶/86锶比例对温度变化敏感。 这种理想的关系已被发现是复杂的有限的实验数据表明，其他因素，如生长动力学可能在这个值中发挥作用。 研究人员使用高温和低温碳酸盐进行了一些初步测量，数据令人鼓舞，88锶/86锶与温度之间似乎有很强的关系。 然而，目前还没有数据能够令人信服地证明在与古气候相关的温度范围内温度的依赖性。 热电离质谱（TIMS）的最新进展加上“双尖峰”方法可以允许足够的准确度和精度来测试这个想法。 此外，斯坦顿堡洞穴的石笋在末次冰期到全新世早期的整个气候波动中生长，是分析的理想选择，并且正在进行中。 锶同位素工作将在一个实验室中进行，该实验室装有新一代放大器，可以获得非常准确和精确的88锶/86锶比率，足以解决与古气候相关的温度变化。 研究人员还将设计一个可以容纳长石笋样品的样品室。该项目的另一个有希望的方面是将新的准分子激光器耦合到电感耦合等离子体质谱仪（ICP-MS）仪器和使用机器学习查看数据的新方法在高通量和高质量元素数据方面的技术成就相结合。研究人员的初步结果表明，一些微量元素，特别是碱金属和碱土金属元素，可能与稳定同位素一致地变化，从而为机器学习应用提供了所需的多维数据。 这些活动在科学上具有重要意义，并且很好地符合EAGER计划的潜在变革性、高风险但潜在高回报的研究属性。该奖项反映了NSF的法定使命，并被认为值得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来支持。