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

北极的沿海地区正在迅速变化，河流流量增加，海岸侵蚀和永久冻土融化，随着地下冰融化，薄而浅的含水层发展。与此同时，对北极沿海地下水的数量、有机和无机营养物含量以及路径的研究不足，人们仍然知之甚少。这项研究将结合联合收割机现场测量和数值模拟来表征地下水流到博福特海泻湖以及它如何在季节和年份之间变化。该项目将培训本科生和研究生，将获得的知识传播到研究区域附近的社区和调查机构附近，包括K-12学生和参与管理北极海岸的当地机构，创建和广播公共教育内容，并提供数据和工具，以帮助了解北极的基本过程。 该项目将提供有关阿拉斯加博福特海沿岸沿着泻湖系统地下水流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-泻湖界面的机制和途径，以及这些机制和途径如何季节性演变; 2）了解季节性变化的通量，来源和不稳定性，地下水来源的溶解有机物和无机营养物输送到沿着阿拉斯加东部博福特海海岸的泻湖。一套方法将包括同位素，地球化学，水文和地球物理场测量的地下水流和溶质运输的土地泻湖界面在春季破冰，夏末开放水域的季节，直到冬季冻结。研究人员将使用计算流和传输模型来解释观察结果并开发物理洞察力。该奖项反映了NSF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而被认为值得支持。

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.