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

University Of Alaska Anchorage Campus, Anchorage AK

Investigators

Abstract

The Arctic region is rapidly changing as average air temperatures, rainfall, glacier and ice sheet melt rates, and depths to the permafrost 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 several Arctic focused institutions and local Greenland communities to develop a platform that increases student participation in hydrology. This platform includes programs like Greenland field research opportunities for 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 shifts 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. A new Arctic focused hydrology course will be taught via distance delivery. This project will also provide 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.