Collaborative Research: RUI: Zero-order to first-order: Hydrologic drivers of surface-subsurface storage dynamics in thawing permafrost landscapes

合作研究：RUI：零阶到一阶：解冻永久冻土景观中地表-地下储存动态的水文驱动因素

• 批准号: 2102338
• 负责人: Sarah Evans
• 金额: $ 27.64万
• 依托单位: Appalachian State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102338&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Zero; order

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Liquid water in the Arctic flows at or near the surface above frozen ground known as permafrost. As permafrost thaws, water flows along new paths, mobilizing previously frozen carbon. If permafrost soils thaw and dry, carbon is released three times more readily than if permafrost soils thaw and remain saturated, implying that water patterns partially control carbon release. Yet, the patterns or drivers of permafrost saturation and how they vary with climate remain poorly understood. This research will use field measurements, remote sensing, and modeling to investigate the dynamics, drivers, and sensitivity of hillslope saturation patterns on the North Slope of Alaska. Results will help to create an ‘H2cOld: Water in the Arctic’ traveling outreach activity for rural K-12 students and communities throughout the southern Appalachians and Idaho. The project will also train four undergraduate students and a graduate student for science careers.The hydrology of Arctic hillslopes underlain by continuous permafrost is largely controlled by water tracks, seasonally saturated zero-order features draining a third of the upland Arctic. Water tracks can rapidly degrade into thermoerosional gullies, the most common Arctic thermoerosional feature, altering seasonal saturation and fluxes of water, nutrients, and sediments. Although water tracks and thermoerosional gullies are the largest and most variable aquatic sources of permafrost carbon release, their saturation dynamics and how these dynamics change as permafrost thaws remain poorly understood. These two features are hypothesized to represent endmembers of the surface network extent of Arctic hillslope hydrology with distinct saturation patterns that are diverging as the climate warms. This research project will test this hypothesis in paired water tracks and thermoerosional gullies in northern Alaska via remote sensing and field campaigns to calibrate a water-energy transport model with variable saturation and freeze-thaw capabilities. Collectively, this work will improve predictions of saturation-controlled carbon release from the Arctic.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.

该奖项的全部或部分资金根据《2021 年美国救援计划法案》（公法 117-2）提供。北极的液态水在称为永久冻土的冰冻地面上或附近流动。随着永久冻土融化，水会沿着永久冻土流动。新的路径，动员以前冻结的碳如果永久冻土解冻并干燥，碳的释放比永久冻土解冻并保持饱和的情况要容易三倍，这意味着水的模式部分控制了碳的释放，然而，人们对永久冻土饱和度的模式或驱动因素以及它们如何随气候变化的方式仍知之甚少。阿拉斯加北坡的山坡饱和模式将有助于为整个阿巴拉契亚山脉南部和爱达荷州的农村 K-12 学生和社区创建“H2cOld：北极的水”旅行外展活动。和一个连续多年冻土下的北极山坡的水文学很大程度上受水道控制，季节性饱和的零级特征排水了北极三分之一的高地，水道可以迅速退化为热侵蚀沟壑，这是最常见的热北极侵蚀。尽管水道和热侵蚀沟壑是永久冻土碳释放的最大且变化最大的水生来源，但它们改变了水、养分和沉积物的季节性饱和度和通量。饱和度动态以及这些动态如何随着永久冻土融化而变化仍然知之甚少，这两个特征被用来表示北极山坡水文学的表面网络范围的端部成员，其饱和度模式随着气候变暖而发生变化。通过遥感和实地活动，在阿拉斯加北部的成对水道和热侵蚀沟壑中校准具有可变饱和度和冻融能力的水能传输模型。总的来说，这项工作将改善对水能传输的预测。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。