High Arctic microclimate and active-layer monitoring: Multi-sensor TOMST TMS-4 soil moisture and temperature network in Hornsund region, SW Spitsbergen (2020–2026)

This dataset provides long-term, high-resolution autonomous microclimatic time series recorded at a 15-minute interval across a distributed network of TOMST TMS-4 dataloggers deployed across the unglaciated Fuglebekken catchment, glaciated Ariebekken and surrounding coastal and tundra environments near the Polish Polar Station Hornsund (SW Spitsbergen, Svalbard).

The TOMST TMS-4 logger is an integrated, robust micro-datalogger designed for long-term ecological, hydrologic, and permafrost studies. Each unit measures:

1. Soil temperature (T_1) at a depth of -6 cm below ground surface

2. Surface / ground temperature (T_2) at 0 cm (soil surface / tundra moss boundary)

3. Air temperature (T_3) at +15 cm above ground level (canopy / near-surface boundary layer)

4. Raw soil moisture signal based on high-frequency capacitance technology integrating the 0 to -14 cm soil depth zone

5. Shake / tilt indicator and logger status flags

This collection provides continuous multi-year records (2020–2026) capturing microtopographic thermal gradients, snow cover duration and insulation dynamics, freeze-thaw timing, active-layer moisture dynamics, and near-surface biological thermal regimes.