Arctic Snow Depth and Sea Ice Thickness from Sentinel-3 Nadir Radiometer and Radar Synergy (NaRRS)

This dataset contains along-track retrievals of Arctic snow depth on sea ice and sea ice thickness derived from the Copernicus Sentinel-3 satellite mission using the Nadir Radiometer and Radar Synergy (NaRRS) method. Temporal coverage spans October through April from the 2016/17 to 2022/23 growth seasons. Spatial coverage extends across the Northern Hemisphere (between 50°N and 81.35°N) where sea ice concentration is ≥ 75%. The primary input dataset to the NaRRS processing is the ESA Sentinel-3 Level 2 Sea Ice Thematic product (Aublanc et al., 2025). The NaRRS method uses a parametric model based on measurements from Sentinel-3's Microwave Radiometer (MWR) and Synthetic Aperture Radar Altimeter (SRAL) to retrieve snow depth on Arctic sea ice. Parameters derived from the Ku-band radar return waveforms were averaged within 23.5 km diameter platelets centered on the provided MWR brightness temperature measurement coordinates prior to combination with the brightness temperature gradient ratio (GR) for input to the parametric model. The resultant snow depths are combined with co-located SRAL-retrieved radar freeboards (also averaged in the platelets) to retrieve sea ice thickness. The input parameters for both snow depth and sea ice thickness retrievals are provided within the dataset, alongside auxiliary sea ice concentration, ice type, and snow and ice density data. The datasets contain unmodified and modified Copernicus Sentinel data. The files are stored in NetCDF4 format in a directory structure corresponding to the Sentinel-3 platform, cycle number, and the original Level 2 Sea Ice Thematic product name.