NSFGEO-NERC: Quantifying the Modern and Glacial Ocean's Carbon Cycle Including Isotopes

NSFGEO-NERC：量化现代和冰川海洋的碳循环（包括同位素）

• 批准号: 1924215
• 负责人: Andreas Schmittner
• 金额: $ 43.15万
• 依托单位: Oregon State University
• 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: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1924215&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Quantifying; Modern; Glacial

The ocean"s carbon cycle is an important part of Earth's climate system because it impacts the concentration of atmospheric carbon dioxide (CO2), which is a greenhouse gas. However, carbon cycling in the ocean is currently not well understood in part because it is influenced by different complex physical, chemical and biological processes. This complicates quantification of changes in ocean carbon storage such as those between the contemporary ocean and that of the Last Glacial Maximum (LGM, ~21,000 years ago) and hinders mechanistic understanding of the reasons for such changes. Previous studies have suggested several explanations for the lower atmospheric CO2 concentrations during the LGM including, increased sea ice cover, more sluggish deep ocean circulation, cooler temperatures and increased dust-borne iron fluxes that fertilized phytoplankton growth. This project will provide a novel data-constrained quantification of these processes, which will improve our mechanistic understanding of past changes, and may improve understanding of possible future projections. A graduate student will be trained in oceanography, biogeochemical and physical modeling. The project will support underrepresented students through more than 25 afterschool Science Technology Engineering and Mathematics clubs in rural Oregon middle and high schools. This will be achieved by working with teachers to develop and implement a carbon cycle and climate science curriculum into their programs. This is a project that is jointly funded by the National Science Foundation's Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own country. Modern observations and paleoclimate data provide a wealth of information on changes to the carbon cycle. These data including carbon and nitrogen isotopes from glacial sediments will be used to constrain process-based models of the modern and LGM ocean. A newly developed method will be applied that provides a precise and complete decomposition of dissolved inorganic carbon storage into preformed and biologically-regenerated components. Preformed carbon is further separated into saturation and disequilibrium components, each of which has physical and biological contributions. Perturbation experiments will be used in which one variable (temperature, sea ice, circulation, soluble iron fluxes) is changed at a time and the carbon decomposition is applied. Uncertainties in circulation, mixing, and biogeochemistry will be considered. Protactinium Thorium ratios (Pa/Th) will be implemented in the model and compared with modern and glacial sediment data, which will provide additional constraints on ocean circulation. Effects of ocean circulation changes on the different carbon components will be investigated. The decomposition will be extended to dissolved oxygen and carbon isotopes (d13C). Hypotheses regarding modern and glacial ocean carbon storage will be tested.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.

海洋的碳周期是地球气候系统的重要组成部分，因为它会影响大气中的二氧化碳（CO2）的浓度，这是一种温室气体。但是，目前对海洋中的碳循环的理解尚未得到很好的理解，部分原因是它受到不同复杂的物理，化学和生物学过程的不同，这会使海洋碳的量化量最大。几年前）并阻碍了对此类变化的理解。未来的预测将接受海洋学的培训，生物地球化学和物理模型将通过超过25个以上的学生在俄勒冈州中学和高中实现的计划来实现这一计划。通过NSF/GEO-NERC领先机构协议，地球科学（NSF/GEO）和国家环境研究委员会（NERC）允许美国/英国的单一联合提案古气候的数据提供了有关碳周期的大量信息。不平衡的成分将使用一个变化（温度，海冰，循环，可溶性铁通量），将使用碳分解，并且在循环，混合和生物体中，将使用碳分解，将使用一个变化（海冰，循环，可溶性铁通量）。沉积物数据将对海洋循环的其他限制。将研究对不同的碳成分的变化，将扩展到溶解的氧气和碳同位素。更广泛的影响审查标准。

项目成果

Projected reversal of the oceanic stable carbon isotope ratio depth gradient with continued anthropogenic carbon emissions

随着持续的人为碳排放，海洋稳定碳同位素比深度梯度的预计逆转

• DOI: 10.1038/s43247-022-00388-8
• 发表时间: 2022
• 期刊: Communications earth environment
• 作者: Kwon, E.Y.

Carbon isotope constraints on glacial Atlantic meridional overturning: Strength vs depth

• DOI: 10.1016/j.quascirev.2021.106844
• 发表时间: 2021-04
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: J. Muglia;A. Schmittner

Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans

• DOI: 10.1126/science.aba7096
• 发表时间: 2020-11-06
• 期刊: SCIENCE
• 影响因子: 56.9
• 作者: Walczak, Maureen H.;Mix, Alan C.;Zellers, Sarah D.
• 通讯作者: Zellers, Sarah D.

Enhanced vertical mixing in the glacial ocean inferred from sedimentary carbon isotopes

• DOI: 10.1038/s43247-021-00239-y
• 发表时间: 2021-04
• 期刊: Communications Earth & Environment
• 影响因子: 7.9
• 作者: S. Wilmes;J. Green;A. Schmittner

Active North Atlantic deepwater formation during Heinrich Stadial 1

• DOI: 10.1016/j.quascirev.2021.107145
• 发表时间: 2021-10
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: J. Repschläger;N. Zhao;D. Rand;L. Lisiecki;J. Muglia;S. Mulitza;A. Schmittner;O. Cartapanis;H. Bauch;R. Schiebel;G. Haug