CAREER: Follow the Water: Understanding River Discharge Dynamics in Rapidly Changing High Northern Latitudes

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The Arctic region is rapidly changing as average air temperatures, rainfall, glacier and ice sheet melt rates, and permafrost depths all increase. However, the connections between these processes and how they influence the discharge, source, and nutrient concentrations of water in Arctic rivers are not well understood. To characterize shifting river source contributions and bridge this knowledge gap, this project will measure multiple components of the water cycle in permafrost watersheds across a range of glacial coverages (including glacier free) in Greenland. Models will test the hypothesis that in the warmer and wetter future Arctic, contributions from flow through the ground to the river will both increase and persist later in the season, which will help offset the loss of river water from steadily decreasing ice masses. Research and education are integrated by collaborating with the Alaska Native Science and Engineering Program, research institutions in Greenland, the Belfer Center’s Arctic Initiative at Harvard University, local Greenland communities, and the University of the Arctic Læra Institute to develop a powerful platform that increases Indigenous Alaskan and Greenland student participation in hydrology. This platform includes programs like Greenland field research opportunities for Indigenous Alaskan and Greenland students and development of Arctic water cycle focused courses. Three important hydrological shifts associated with a warmer and wetter High Arctic Greenland occurred within the last million years: 1) increased freshwater from glacier melt; 2) deepening active layer (permafrost thaw); and 3) increased precipitation. Current climate changes are leading to an Arctic Greenland more like these past environments. A warmer Arctic will likely increase active layer depths, which when coupled with greater rain expected in the Arctic, could result in more flow through the active layer contributing to river discharge, but this remains unknown. This project will measure multiple components of the water cycle in permafrost watersheds across a range of glacial coverages (including glacier free) in High Arctic Greenland. These data will characterize shifting river source contributions and provide critical field data needed to calibrate novel numerical hydrological models. These models will then help test river discharge hypotheses given future Arctic change under different climate scenarios (e.g., more precipitation, deeper active layer). These analyses will help understand how increased active layer flow could mitigate the hydrological impact of glacier recession and future transition to ice-free watersheds. This project will support graduate and undergraduate students and develop a powerful multifaceted platform to increase participation in STEM fields of Indigenous Alaskan and Greenland students. A new Arctic focused hydrology course will be taught via distance delivery and leverage relationships to bring together Indigenous Alaskan and Greenland students. This project will also provide Indigenous Alaskan and Greenland undergraduate students with a transformative experience learning together in the field while working with researchers. Larger societal benefits include understanding how the Arctic water cycle is changing, which can impact the global water cycle, freshwater resources, and climate patterns across Earth.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.