OPP-PRF: Organic Matter Export, Processes, and Transformations Drive Carbon Cycling Patterns in the Arctic Ocean

OPP-PRF：有机物出口、加工和转化驱动北冰洋的碳循环模式

基本信息

批准号：
2138584
负责人：
Jumanah Hamdi
金额：
$ 30.25万
依托单位：
Louisiana Universities Marine Corsortium
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-10-01 至 2023-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2138584&HistoricalAwards=false
关键词：
OPP PRF Organic Matter Export

项目摘要

Global carbon cycling supports life on Earth and affects marine, terrestrial, and atmospheric ecosystems. Human activities alter the balance of this natural cycle by adding fossil carbon to the contemporary atmosphere, thereby changing our climate. As the climate warms, reduced sea ice cover and increased Arctic river carbon export dramatically change the microscopic organic molecules in the oceans. These compounds play essential roles in Earth’s natural elemental cycles, contribute to the storage of atmospheric greenhouse gasses (e.g., carbon dioxide, CO2) in the ocean, and support marine organisms. Therefore, with large-scale ecosystem changes across the Arctic, the time is now to better understand what microscopic materials in the Arctic Ocean will shape the composition and function of all other Earth’s oceans. Concerning the prediction that the Arctic Ocean will be ice-free around 20–50 years from now, this research is designed to understand Arctic Ocean carbon cycling processes and impacts, such as further biological and chemical feedback loops as well as CO2 outgassing from microscopic carbon-based materials, such as dissolved organic matter (DOM), altered in mineralization processes. Much of the DOM exported from the Arctic is riverine and is funneled through the Fram Strait, a relatively small body of water that connects the Arctic Ocean to the global conveyor belts. This is important because Fram Strait represents a linkage of Arctic terrestrial carbon to other ocean environments. The researchers will measure the amount and type of DOM responsible for the largest transformations in the ocean resulting in increased concentrations of CO2 in the atmosphere. Providing essential molecular-level chemical data is needed to understand DOM signatures within the context of global change and will provide the scientific community with definitive DOM data. The researchers also embrace this work as an ideal opportunity to spearhead a carbon chemistry initiative across diverse Arctic science researchers to lead to safer and healthier carbon characterization practices. Global environmental change impacts Arctic ice sheets, sea ice, ocean, and circulation, affecting ecosystem function and carbon cycling in marine waters. As the climate warms, sea ice diminishes, ice sheet loss from Greenland increases, and Arctic river-carbon (C) outputs increase, making the Arctic Ocean a mixing zone of diverse organic material (OM) that gets funneled through the Fram Strait before circulating globally. Thus, the Fram Strait is poised to dramatically impact marine surface and bottom waters resulting in carbon dioxide (CO2) emissions upon OM mineralization through natural processes. Marine C mineralization processes depend on dissolved OM (DOM) composition, microbes, nutrient availability, and sunlight exposure, all of which shape the mechanisms for CO2 outgassing from transformed DOM. The overarching hypothesis is DOM molecular composition distinctions between microbial and photochemical mineralization of DOM to CO2 in Fram Strait are driven by the heterogeneous nature of diverse Arctic Ocean sources. Advanced analytical chemistry measurements of DOM (ultrahigh resolution mass spectrometry, C isotopic composition, and nuclear magnetic resonance spectroscopy) will be used to decipher molecular composition and unique C markers from biotic and abiotic degradation mechanisms occurring in the Fram Strait. As a result, linkages of DOM composition and CO2 outgassing will be made. This work will target how DOM can persist and be transformed in the Fram Strait across rapid and prolonged time scales. Progress in mapping microbe- and photochemical-DOM interactions in the Fram Strait will address knowledge gaps across seemingly disparate fields, culminating in better understandings of C cycling in the Arctic. The data will provide the community with definitive DOM compositional markers that can be used to better understand Arctic marine waters and help enforce healthy environmental policy as the climate warms and sea levels rise. Analytical and green chemistry expertise will be combined to identify improvements in Arctic C research which will be essential for the next generation of Arctic researchers.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.

全球碳循环支持地球上的生命，并影响海洋，陆地和大气生态系统。人类活动通过在当代气氛中添加化石碳来改变自然周期的平衡，从而改变我们的气候。随着气候的变暖，海冰覆盖率减少并增加了北极河碳的出口，极大地改变了海洋中的微观有机分子。这些化合物在地球的自然元素周期中起着重要作用，有助于大气温室气体（例如，二氧化碳，CO2）在海洋中的储存，并支持海洋生物。因此，随着大规模生态系统在北极的变化，现在是时候更好地了解北极海洋中哪些显微镜材料将影响所有其他地球海洋的组成和功能。关于北极海将在20到50年内将无冰的预测，这项研究旨在了解北极海洋碳循环过程和影响，例如进一步的生物学和化学反馈回路，以及二氧化碳量以及从微观碳基材料（例如溶解有机物（DOM），更改矿物化过程中的二氧化碳材料）。从北极出口的大部分DOM是河流，并通过弗拉姆海峡（Fram Strait）进行了漏斗，这是一种相对较小的水，将北极海洋连接到全球输送带。这很重要，因为Fram海峡代表了北极陆碳与其他海洋环境的联系。研究人员将测量负责海洋中最大变化的DOM的数量和类型，从而导致大气中的二氧化碳浓度增加。需要提供基本的分子级化学数据，以了解全球变化背景下的DOM签名，并将为科学界提供明确的DOM数据。研究人员还将这项工作是一个理想的机会，可以将北极科学研究人员的碳化学计划带动碳化学计划，从而导致更安全，更健康的碳特征实践。全球环境变化影响北极冰盖，海冰，海洋和循环，影响海水中的生态系统功能和碳循环。随着气候的变暖，海冰减少，绿地的冰层损失增加，北极河碳（C）的输出增加，使北极海洋成为潜水员有机材料（OM）的混合区，在全球循环之前，该区域通过Fram Strait漏斗。这就是弗拉姆海峡被中毒，以极大地影响海洋表面和底水，从而在OM矿化中通过自然过程在OM矿化后产生二氧化碳（CO2）的排放。海洋C矿化过程取决于溶解的OM（DOM）组成，微生物，养分可用性和阳光暴露，所有这些都塑造了从转化的DOM中添加CO2的机制。总体假设是微生物和光化学矿化之间的DOM分子组成区别在FRAM海峡中是由潜水员北极海洋来源的异质性驱动的。 DOM的晚期分析化学测量值（超高分辨率质谱，C同位素组成和核磁共振光谱）将用于破译分子组成和来自生物和非生物降解机制的独特C标记。结果，将建立DOM组成和二氧化碳的链接。这项工作将针对DOM如何在快速和延长的时间尺度上持续并在Fram海峡中转变。在构图中，绘制框架海峡中的微生物和光化学 - 差异相互作用的进展将解决看似不同的领域的知识差距，从而提高了对北极C循环的更好理解。这些数据将为社区提供定义的DOM组成标记，可用于更好地理解北极海水，并随着攀登温暖和海平面上升而有助于执行健康的环境政策。将联合使用分析和绿色化学专业知识，以确定北极C研究的改进，这对于下一代北极研究人员至关重要。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子的优点和更广泛的影响来审查标准，认为NSF的法定任务被认为是宝贵的支持。