ORE-CZ: Riverine Biogeochemical Export From High-Latitude Catchments: The Role of Glaciers and Extreme Hydrologic Events

ORE-CZ：高纬度流域的河流生物地球化学输出：冰川和极端水文事件的作用

• 批准号: 2227821
• 负责人: Jason Fellman
• 金额: $ 19.99万
• 依托单位: University of Alaska Southeast Juneau Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2227821&HistoricalAwards=false
• 关键词: ORE; CZ; Riverine; Biogeochemical; Export

Northern regions like Alaska are currently warming twice as fast as the global average. This warming is melting glaciers, which changes the flow of water in streams and can trigger the onset of flood events known as “outbursts” in rivers beneath glaciers. Changes in the way that water flows through watersheds also has implications for the quality of water being transported by rivers to the ocean. This project will evaluate how changing glaciers influence the movement of streamwater, nutrients, and minerals from watersheds along the Alaskan coast to the nearshore waters in the Gulf of Alaska. Project personnel will sample rivers with glaciers throughout the year and intensively during large storms and “outburst” floods. The project will provide critical information about how climate change will impact the flow of freshwater and nutrients into food webs in downstream marine environments. This is important because the Gulf of Alaska contains one of the most productive marine fisheries on Earth. The project will also provide skills and training for undergraduate students at the University of Alaska Southeast, providing them the opportunity to become the next generation of earth scientists. Finally, project leaders and students will work closely with the Mendenhall Glacier Visitor Center in Juneau to develop outreach materials for educating visitors about the environmental impacts of glacier change.Climate change, extreme events, and land-cover transformation are triggering dramatic changes to the Earth’s critical zone. Disturbances to the catchment hydrologic cycle, such as the melting of glaciers, are particularly consequential because water is involved in all critical zone processes. Therefore, understanding changes to the timing and magnitude of water flow through catchments and its influence on critical zone structure and processes, such as biogeochemical cycling, is central to critical zone science. This project will use in-situ sensors and manual measurements to quantify yields of carbon, nitrogen, and phosphorus as well as mercury in coastal watersheds of southeast Alaska experiencing rapid glacier recession. Extreme hydrologic events, such as atmospheric rivers and glacial lake outburst floods will also be sampled intensively to evaluate their impacts on riverine biogeochemical budgets. By sampling above and below a pro-glacial lake, we will also examine the role that these ubiquitous features of glacier watersheds play in modulating downstream flows of sediments and solutes. Undergraduate students from the University of Alaska Southeast will be involved in all aspects of the project including sensor deployment, data collection, laboratory analysis, and presentation of project results.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.

阿拉斯加等北部地区目前的变暖速度是全球平均速度的两倍。这种变暖正在融化冰川，这改变了溪流中的水流，并可能引发冰川下河流中被称为“爆发”的洪水事件。水流经流域的方式的变化也对由河流输送到海洋的水的质量产生影响。该项目将评估冰川变化如何影响从阿拉斯加海岸流域到阿拉斯加湾近岸水域的水流、营养物质和矿物质的运动。项目人员将全年对有冰川的河流进行采样，在大风暴和“突发”洪水期间进行密集采样。该项目将提供有关气候变化如何影响下游海洋环境中淡水和营养物质流入食物网的关键信息。这一点很重要，因为阿拉斯加湾拥有地球上最多产的海洋渔场之一。该项目还将为阿拉斯加东南大学的本科生提供技能和培训，为他们提供成为下一代地球科学家的机会。最后，项目负责人和学生将与朱诺的门登霍尔冰川游客中心密切合作，开发宣传材料，向游客宣传冰川变化对环境的影响。气候变化、极端事件和土地覆盖变化正在引发地球关键地带的剧烈变化。对集水区水文循环的干扰，如冰川融化，后果特别严重，因为所有关键的带过程都涉及到水。因此，了解通过集水区的水流时间和幅度的变化及其对关键带结构和过程的影响，如生物地球化学循环，是关键带科学的核心。该项目将使用原位传感器和人工测量来量化阿拉斯加东南部沿海流域的碳、氮、磷和汞的产量，这些流域正在经历冰川快速消退。极端水文事件，如大气河流和冰湖溃决洪水也将集中采样，以评估其对河流生物地球化学收支的影响。通过在前冰湖的上方和下方取样，我们还将研究冰川流域这些无处不在的特征在调节沉积物和溶质的下游流动中所起的作用。阿拉斯加东南大学的本科生将参与项目的各个方面，包括传感器部署、数据收集、实验室分析和项目结果展示。该奖项反映了美国国家科学基金会的法定使命，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。