Time series of satellite laser and radar altimetry observations over landfast Arctic sea ice

This data set is the supplementary material to:Taelman, C., Landy, J., Mallett, R., and Itkin, P.: Empirical evidence of overestimated Ku-band sea ice radar freeboards in satellite altimetry, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2026-1662, 2026. The data set contains a time series over Arctic landfast sea ice over the geographical area of Belgica Bank (northeast off the coast of Greenland) between January and August 2022. The following observations are available: satellite laser and Ku-band radar altimetry, satellite C-band SAR, meteorological data (in situ + reanalysis). We also provide the polygon outlines of the different study sites (regions of interest, ROIs). # ---------------------------------------------------- #Dataset is structured as follows: altimetry\ Contains the time series of satellite Ku-band radar altimetry observations (from CryoSat-2 & Sentinel-3) and satellite laser altimetry observations (from ICESat-2). original_FB: files containing the along-track altimetry samples over the study sites (timestamp and corresponding radar/laser freeboard). Note that these are radar freeboards (not ice freeboards), so the values are not corrected for delayed radar wave propagation in the overlying snow cover! interpolated_FB_SD_SIT: files containing the daily interpolated laser and radar freeboards, as well as snow depth (SD) and sea ice thickness (SIT) derived from these dual-frequency freeboard measurements. Snow and ice density values used in the calculations are also provided here, alongside the precipitation data from CARRA reanalysis (used as comparison). radar_waveform_parameters: leading-edge width, pulse peakiness, sigma0 radar backscatter coefficient. Given per ice type. Original version contains median and IQR values per altimeter crossing, while interpolated version contains daily interpolated values. SAR\ Contains the time series of satellite C-band SAR backscatter (sigma0) for HH and HV polarisations (from Sentinel-1). MET_data\meteorological data: 2m air temperatures from CARRA reanalysis and the Henrik Krøyer Holme (HKH) weather station in situ air and snow/ice interface temperatures recorded by the mass balance buoy SIMBA NPI0801.Note: precipitation data from CARRA reanalysis is included in the altimetry folder, in the files in 'interpolated_FBS_SD_SIT' shapefiles\ ROI_polygons_FYI: polygon outlines of first-year ice (FYI) regions of interest (ROIs). ROI_polygons_FYI: polygon outlines of multi-year ice (FYI) regions of interest (ROIs). BelgicaBank_ROI: polygon outline covering the study area (large area that includes all ROIs). fast_ice_BB_Feb_May_2022: polygon outline of the approximate fast ice edge between February-May 2022 (outline delineates the stable part of the fast ice over this entire time period).Note: the 4 digits at the end of the filenames indicate the EPSG code used (3996 or 4326). ROIs_formation_breakup_dates.txt File containing the date of formation and date of breakup for each individual region of interest (ROI) used in the study.