Evolution of snow and firn on the Juneau Icefield, Alaska (2025)

Collectively, Alaskan glaciers contribute 25 percent (%) of the global land-ice loss to sea-level rise, and most lose mass through surface melting due to increasing atmospheric temperatures. Snow and firn properties impact the retention and runoff of snow melt in the glacier, and are therefore an important connection between the suprglacial, englacial, and subglacial hydrological systems. We use field observations to investigate changes in the thermal and physical properties of snow and firn on the Juneau Icefield, Alaska during summer of 2025. The first dataset contains measurements collected during June 2025 field season three sites on the Juneau Icefield: a site at the Matthes-Llewellyn Divide (MLD); at the Northwest Branch of the Taku Glacier (NWB1); and at a firn-covered site in the current ablation zone of the Taku Glacier (TKG4). These include density, permittivity, grain size, and temperature. The document "Juneau_Icefield_Core_and_Pit_Data_2025.csv" contain these data for all sites. The second dataset contains data derived from a self-potential system (Clayton, W. S. (2022). Measurement of unsaturated meltwater percolation flux in seasonal snowpack using self-potential (SP). Journal of Glaciology, 68(267), 25–40. doi:10.1017/jog.2021.67), which includes a weather station and electrodes placed into the snow with the possibility of measuring melt infiltration. These data include wind speed, wind direction, air temperature, relative humidity, incoming shortwave, reflected shortwave, incoming longwave, outgoing longwave, albedo, self-potential across electrode pairs, potential difference between reference electrodes, and effective relative permittivity. The documents "SP_data_logger1_06_23_2025_download_TKG4.csv," "SP_data_logger1_06_27_2025_download_TKG4.csv" and "SP_data_logger2_06_26_2025_download_TKG4.csv" and “SP_data_logger2_06_29_2025_download_TGK4.csv” contain these data for one site in the ablation zone (TKG4) that still has snow and firn cover. Clayton, W.S. (2022) Measurement of unsaturated meltwater percolation flux in seasonal snowpack using self-potential. Journal of Glaciology, 68(267), pp.25-40.