Here,we characterized the processes controlling active-layer freezing in Arctic Alaska using an integrated approach combining in situ soil measurements, local-scale ( ∼ 50 m) longwave radar retrievals from NASA airborne P-band polarimetric SAR (PolSAR) and a remote-sensing-driven permafrostmodel. To better capture landscape variability in snow coverand its influence on the soil thermal regime, we downscaledglobal coarse-resolution (∼ 0:5◦) MERRA-2 reanalysis snowdepth data using finer-scale (500 m) MODIS snow cover extent (SCE) observations.