Field, laboratory, and modeling studies of water infiltration and runoff in subfreezing snow on regional scales to estimate future greenhouse-induced changes in sea-level. Final report

摘要

The current DOE-supported research program (Reduce Uncertainty in Future Sea-Level Change Due to Ice Wastage) addressed the question of how the refreezing of meltwater in cold snow affects sea-level changes in a future changing climate. The continuation of that research, proposed here, takes an additional new approach by focusing on processes which can be defined and characterized by measurements on regional scales. This new emphasis is intended to be directly applicable to a large-scale analysis from which runoff forecasts (and consequent sea level change) from the entire arctic region can be made. The research proposed here addresses the problem of forecasting future sea-level change due to greenhouse-induced changes in runoff from polar glaciers and ice caps. The objectives of this work are (1) to observe in the field the processes of infiltration and refreezing which lead to the formation of impermeable firn layers; (2) to reproduce these observed processes in the laboratory to confirm and further quantify their understanding; (3) to develop and calibrate a regional scale numerical model which can simulate these processes, based on measured parameters and driven by boundary conditions determined by climate; and (4) to apply this model to predict the development of impermeable firn (and consequent runoff and discharge to the ocean) in response to predicted future climate change.