EAR-PF: Uncovering climate-driven impacts on high-latitude aquifer-ocean exchange

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Dr. Julia A. Guimond has been granted an NSF EAR Postdoctoral Fellowship to study coastal high-latitude hydrology at Dalhousie University in collaboration with the Water Cycle Branch of the U.S. Geological Survey. Through field data collection and numerical modeling analyses, this research will investigate interactions between high-latitude groundwater reservoirs and the coastal ocean. In the Arctic and subarctic, water flow patterns and storage are rapidly changing due to pronounced atmospheric warming. Alterations in groundwater flow and aquifer-ocean connectivity due to permafrost thaw will have profound impacts on global climate and high-latitude coastal zones, including marine and freshwater resources. Coastal systems are particularly vulnerable to climate-induced change due to changes in sea level and sea ice in addition to permafrost distribution. The primary goal of this research is to identify the mechanisms mediating aquifer-ocean exchange in permafrost regions to better understand how these processes will be modified under changing climatic conditions. Results from this study will help inform water and marine-resource management and climate adaptation strategies for Indigenous communities and northern governments and identify where coastal water resources are most vulnerable to climate change-induced contamination mobilization.The integrated field and modeling study undertaken by Dr. Guimond aims to unravel the feedbacks between climate change and aquifer-ocean exchange in high-latitude permafrost regions. Results will identify the factors influencing Arctic and subarctic submarine groundwater discharge and saltwater intrusion and characterize the spatial and temporal scales over which they occur, improving predictive capacity under changing climatic and hydrologic conditions. Results of this study will enhance our knowledge of 1) present-day rates of groundwater discharge to the ocean, 2) processes controlling aquifer-ocean exchange in permafrost-bound regions, and 3) aquifer-ocean exchange response to climate-induced change (e.g. permafrost thaw). The field portion of this study will be conducted in Sanikiluaq, Canada and in Cambridge Fjord, Baffin Island, Canada. A suite of hydrogeological and geochemical field tools and methods will be used to assess present-day conditions, such as conductivity, temperature, depth loggers and radium isotopes. Also, numerical, hydrological models with freeze-thaw, coupled surface-subsurface processes, and variable density capabilities will be used to expand understanding in space and time. The processes and mechanisms elucidated through this integrated study will promote development of new conceptual and quantitative models that predict feedbacks between climate-change driven permafrost thaw and land-sea water exchange in high-latitude coastal systems that can inform groundwater management policies. The PI will help develop a cyber-seminar series as educational outreach to the broader geoscience community on climate-change driven issues in Arctic and subarctic regions. The Hydrological Science program in the Earth Science division provided co-funding for this fellowship.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.