This dataset provides high-resolution multi-depth continuous time series of volumetric soil water content (soil moisture), ground temperature, and bulk electrical conductivity (EC / apparent salinity proxy) monitored across the active layer in the unglaciated Fuglebekken catchment near the Polish Polar Station Hornsund (SW Spitsbergen, Svalbard).
Profiling was carried out using three fully encapsulated Sentek Drill & Drop Triscan probe devices:
· Probe BT004422
· Probe BT003311
· Probe BT003272
Each probe is 1.20 m in length and equipped with 12 sensor arrays positioned every 10 cm along the vertical profile (0.05 m / 0.10 m down to 1.20 m depth). The probes operate based on high-frequency capacitance technology for volumetric water content (VWC), thermistors for soil temperature, and high-frequency impedance measurements for bulk electrical conductivity (EC, providing insights into pore-water salinity dynamics and phase transitions).
The probes were installed directly into pre-drilled, undisturbed tapered soil holes to preserve natural soil stratigraphy, root structures, and ground thermal coupling without annular packing disturbances. The data record active layer thaw front progression, freeze-back dynamics, infiltration pulses from summer precipitation and snowmelt, and near-surface salinity variations.
Funding notice: Field installations and monitoring from 2022 to 2025 were funded by the National Science Centre, Poland under grant no. UMO-2020/38/E/ST10/00139 (SONATA