EAR-PF: Clumped and Triple Oxygen Isotopes of Terrestrial Carbonates: New Tools to Estimate Aridity and Precipitation in California During Past Greenhouse Climates

EAR-PF：陆地碳酸盐的团簇和三重氧同位素：估计过去温室气候期间加利福尼亚州干旱和降水的新工具

• 批准号: 1854873
• 负责人: Julia Kelson
• 金额: $ 17.4万
• 依托单位: Kelson, Julia Rae
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1854873&HistoricalAwards=false
• 关键词: EAR; PF; Clumped; Triple; Oxygen

Dr. Julia Kelson has been granted an NSF EAR Postdoctoral fellowship to carry out research and educational activities at the University of Michigan, Ann Arbor. This project investigates the water cycle during climates that are characterized by atmospheres with high concentrations of greenhouse (heat-trapping) gases like carbon dioxide. As long as atmospheric concentrations of greenhouse gases continue to increase, we may observe more evaporation and more seasonally intense precipitation (rain/snow) in future climates. One way to understand such changes in the intensity of the hydrologic cycle is to explore the record of evaporation and precipitation during ancient high carbon dioxide climates, such as those of the early Cenozoic time period (65-30 million years ago). This project will develop a new tool to estimate the intensity of evaporation using ancient soil carbonates and mollusk shells. The chemical composition of these ancient carbonate materials contains information about the temperature of formation and the extent to which the rain/ground water from which they grew was affected by evaporation. Thus, this tool will allow for a simultaneous estimate of earth surface temperature and of aridity. The investigator will convey the importance of understanding ancient environmental change through outreach programs affiliated with the University of Michigan. One program is Earth Camp, which brings underrepresented high school students at no-cost to the university and to the field. Another program is Females Excelling More in Math and Engineering Sciences (FEMMES), which encourages girls to explore their potential in science. This project is leveraging two novel stable carbonate isotope measurements to improve our ability to reconstruct aridity and precipitation of ancient climates. This research consists of two components: 1) a modern calibration study, where the isotopic composition of modern soil carbonates and mollusk shells are measured, along with the isotopes of modern meteoric waters, to add to the growing understanding of how the isotopic composition of carbonates reflect their environment, and 2) an application to an ancient greenhouse climate, where these new proxies are applied to a Paleocene section in California that has both paleosol carbonates and mollusks in order to reconstruct past aridity and moisture sources. By targeting environments where marine and terrestrial carbonates are collocated, the investigator can understand the potential seasonal biases that the carbonate materials may impart as well as different aspects of the hydrologic cycle.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.

朱莉娅·凯尔森博士已被授予NSF博士后奖学金，在密歇根大学安阿伯开展研究和教育活动。该项目研究了以高浓度温室（吸热）气体（如二氧化碳）为特征的气候条件下的水循环。只要大气中温室气体浓度继续增加，我们就可能在未来的气候中观察到更多的蒸发和更多的季节性强降水（雨/雪）。了解这种水文循环强度变化的一种方法是探索古代高二氧化碳气候期间的蒸发和降水记录，例如新生代早期（6500万至3000万年前）。该项目将开发一种新的工具，利用古老的土壤碳酸盐和软体动物壳来估计蒸发强度。这些古代碳酸盐物质的化学成分包含了有关形成温度的信息，以及它们生长的雨水/地下水受到蒸发影响的程度。因此，这一工具将允许同时估计地球表面温度和干旱度。研究人员将通过密歇根大学附属的外展计划传达了解古代环境变化的重要性。其中一个项目是地球营，它将代表性不足的高中生免费带到大学和实地。另一个方案是“女性在数学和工程科学方面更出色”，该方案鼓励女孩探索她们在科学方面的潜力。该项目利用两种新的稳定碳酸盐同位素测量来提高我们重建古代气候的干旱和降水的能力。这项研究包括两个部分：1）现代校准研究，其中测量现代土壤碳酸盐和软体动物壳的同位素组成，沿着现代大气沃茨的同位素，以增加对碳酸盐的同位素组成如何反映其环境的日益增长的理解，以及2）对古代温室气候的应用，其中这些新的替代物被应用于加州的古新世剖面，该剖面具有古土壤碳酸盐和软体动物，以重建过去的干旱和水分来源。通过针对海洋和陆地碳酸盐共存的环境，研究人员可以了解碳酸盐物质可能带来的潜在季节性偏差以及水文循环的不同方面。该奖项反映了NSF的法定使命，并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，被认为值得支持。

项目成果

Dynamics of Pedogenic Carbonate Growth in the Tropical Domain of Myanmar

• DOI: 10.1029/2021gc009929
• 发表时间: 2022-07-01
• 期刊: GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
• 影响因子: 3.5
• 作者: Licht, A.;Kelson, J.;Aung, Day Wa
• 通讯作者: Aung, Day Wa

Triple oxygen isotope compositions of globally distributed soil carbonates record widespread evaporation of soil waters

• DOI: 10.1016/j.gca.2023.06.034
• 发表时间: 2023-08
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: J. Kelson;T. Huth;B. Passey;N. Levin;S. Petersen;P. Ballato;E. Beverly;D. Breecker;G. Hoke;A. Hudson;Haoyuan Ji;A. Licht;Erik J. Oerter;J. Quade

Looking upstream with clumped and triple oxygen isotopes of estuarine oyster shells in the early Eocene of California, USA

向上游观察美国加利福尼亚州始新世早期河口牡蛎壳的聚集和三氧同位素

• DOI: 10.1130/g49634.1
• 发表时间: 2022
• 期刊: Geology
• 影响因子: 5.8
• 作者: Kelson, Julia R.;Petersen, Sierra V.;Niemi, Nathan A.;Passey, Benjamin H.;Curley, Allison N.
• 通讯作者: Curley, Allison N.