OPP-PRF: Linking the Physical and Chemical Drivers of Carbon Cycling in Arctic Source-to-sink Systems

OPP-PRF：将北极源-汇系统中碳循环的物理和化学驱动因素联系起来

• 批准号: 2419995
• 负责人: Marisa Repasch
• 金额: $ 32.86万
• 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: 2024
• 资助国家: 美国
• 起止时间: 2024-01-15 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2419995&HistoricalAwards=false
• 关键词: OPP; PRF; Linking; Physical; Chemical

The global carbon cycle regulates the climate and habitability of our planet. The Arctic landscape, particularly permafrost (frozen ground), stores a massive amount of carbon – nearly twice as much as the atmosphere. As air temperatures in the Arctic increase, the permafrost thaws and carbon-rich organic matter can be released. Once released, this carbon can be transformed into carbon dioxide and methane – greenhouse gases. The carbon released from permafrost may also be transported to the ocean where it can be buried for many years, keeping it out of the atmosphere. The primary goals of this research are to find hotspots of permafrost thaw in the Arctic landscape and to understand what happens to carbon after it is released from the permafrost. This project supports one postdoctoral scholar and provides funding to analyze samples collected from a river in Arctic Alaska. This work will result in a mathematical model that simulates the flow of carbon across the Arctic landscape. The PI will also create an educational tool to teach students about carbon-climate feedbacks.This project aims to develop a mechanistic understanding of the feedbacks between physical erosion, oxidative weathering, and organic carbon (OC) transformation in Arctic landscapes. This project uses a “source-to-sink” approach to study the physical and chemical effects of permafrost thaw at the landscape-scale and assess the transformation of OC upon mobilization and downstream transport. Focusing on the Canning River in northern Alaska, the PI will compare modern river OC fluxes with long-term catchment-average OC export derived from cosmogenic radionuclide geochemistry. To determine whether permafrost-derived OC is oxidized to CO2 during transport across the Arctic landscape, this project applies novel geochemical methods, including ramped pyrolysis oxidation-14C and dissolved rhenium analyses. The results will constrain decomposition rates of OC mobilized from thawing permafrost, which are largely unknown but needed to predict future CO2 emissions from the Arctic. Using data generated from this project, the PI will construct a model of coupled erosion, weathering, and carbon cycling in Arctic river catchments. Further application of this coupled model will reveal the feedbacks among climate, erosion, sediment routing, and OC cycling that will advance our understanding of Arctic landscape response to future climate change.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.

全球碳循环调节我们星球的气候和宜居性。北极景观，尤其是多年冻土（冷冻地面），存储了大量碳，几乎是大气的两倍。随着北极空气温度的升高，可以释放永久冻土和富含碳的有机物。释放后，该碳可以转化为二氧化碳和甲烷 - 温室气体。从多年冻土释放的碳也可能被运送到可以建造多年的海洋，使其无法脱离大气。这项研究的主要目标是在北极景观中找到永久冻结融化的热点，并了解碳从永久冻土释放后会发生什么。该项目支持一项博士后科学，并提供资金来分析从北极阿拉斯加河流收集的样本。这项工作将导致一个数学模型，该模型模拟碳在北极景观中的流动。 PI还将创建一种教育工具，以向学生传授碳气候反馈。该项目旨在对北极景观中物理侵蚀，氧化风化和有机碳（OC）转化之间的反馈进行机械理解。该项目使用一种“来源对链接”方法研究景观规模上多年冻土融化的物理和化学作用，并评估动员和下游运输后OC的转化。 PI专注于阿拉斯加北部的坎宁河，将现代河流通量与从宇宙辐射辐射化学衍生的长期流域平均OC出口进行比较。为了确定在整个北极景观运输过程中是否将多年冻土衍生的OC氧化为CO2，该项目采用了新型的地球化学方法，包括加速的热解氧化14C和溶解的rhenium分析。结果将限制OC的分解速率动员从融化的多年冻土中，这在很大程度上未知，但需要预测北极的未来二氧化碳排放。使用该项目产生的数据，PI将在北极河流集水区中构建一种耦合侵蚀，风化和碳循环的模型。该耦合模型的进一步应用将揭示攀登，侵蚀，沉积物路由和OC循环之间的反馈，这将提高我们对北极景观对未来气候变化的反应的理解。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力和更广泛的影响来通过评估来获得支持的珍贵的，否则将珍贵。