Collaborative Research: The physical and chemical dynamics of groundwater flow across the land-sea interface in Arctic lagoon ecosystems

随着河流流量的增加、海岸侵蚀和永久冻土的融化，北极沿海地区正在迅速变化，随着地下冰的融化，又薄又浅的含水层开始形成。与此同时，对北极沿海地下水的数量、有机和无机营养成分以及通道的研究还不够充分，对它们的了解仍然很少。这项研究将结合实地测量和数值模拟来表征波弗特海泻湖的地下水流量，以及它如何随季节和年份变化。该项目将培训本科生和研究生，将获得的知识传播到靠近研究区域和调查员机构附近的社区，包括K-12学生和参与管理北极海岸的当地机构，为公共教育创建和广播内容，并提供数据和工具，以帮助了解北极的基本过程。该项目将提供关于阿拉斯加波弗特海岸泻湖系统中地下水流动和生物地球化学过程的基本新知识。主要研究目标是：1)确定地下水流经陆地-泻湖界面的机制和路径，以及这些机制和路径的季节性演变；2)了解输送到阿拉斯加东部波弗特海岸泻湖的地下水溶解有机物和无机营养物的季节变化通量、来源和不稳定性。一套方法将包括同位素、生物地球化学、水文学和地球物理实地测量地下水流量和溶质运输通过陆地-泻湖界面在春季融冰，夏季晚些时候开放的季节，直到冬季冻结。研究人员将利用计算流和传输模型解释观测结果并发展物理洞察力。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。

Coastal areas in the Arctic are changing rapidly, with increases in river flow, coastal erosion, and permafrost thaw, and as underground ice melts, thin, shallow aquifers develop. At the same time, the amount, organic and inorganic nutrient content, and pathways of coastal groundwater have been understudied and remain poorly understood in the Arctic. This study will combine field measurements and numerical modeling to characterize groundwater flow to Beaufort Sea lagoons and how it changes across seasons and years. The project will train undergraduate and graduate students, disseminate the knowledge gained to communities close to the study area and near the investigators’ institutions, including K-12 students and local agencies involved in managing the Arctic coast, create and broadcast content for public education, and provide data and tools to help understand fundamental processes in the Arctic. This project will provide fundamental new knowledge regarding groundwater flow and biogeochemical processes in lagoon systems along the Alaskan Beaufort Sea coast. The primary research objectives are: 1) to determine the mechanisms and pathways for groundwater flow across the land-lagoon interface and how these mechanisms and pathways evolve seasonally; and 2) to understand seasonally-varying fluxes, sources, and lability of groundwater-derived dissolved organic matter and inorganic nutrients delivered to lagoons along the eastern Alaskan Beaufort Sea coast. A suite of methods will include isotopic, biogeochemical, hydrologic, and geophysical field measurements of groundwater flow and solute transport across the land-lagoon interface during spring ice-break-up, later summer open water season, and until winter freeze up. The investigators will interpret the observations and develop physical insight using computation flow and transport modeling.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.