In the face of climate change transforming snow cover and permafrost in the Arctic, it is important to enhance our understanding of how snowmelt interacts with the environment. Here, we use stable isotopes of 17O, 18O and 2H coupled with hydro-chemical tracers and process-based modelling, to trace snowmelt from the evolution of the snowpack to river runoff and groundwater recharge in a coastal Arctic environment. The study is based on the data obtained from an unglaciated Fuglebekken catchment of 1.27 km2 situated in the southwest Spitsbergen. This area represents sea terraces and coastal mountain catchments that are becoming increasingly common with deglaciation. We reveal the dynamics of the snowmelt partitioning between surface runoff and underground recharge throughout the summer season. Change in isotopic content within the snow profile during snowpack evolution indicates significant fractionation processes. The study underlines the importance of accurately addressing uncertainties when using the isotopic hydrograph separation method and discusses possibilities for tackling these uncertainties.

Presentation given by Ekaterina Rets on 01.05.2025 at the EGU General Assembly 2025 in the session HS2.1.3 "Improving Measurement, Understanding, and Prediction of the Mountain Cryosphere and Hydrological Cycle through Alpine Research Catchments"