Snow Depth Estimation on Lead-less Landfast ice using Cryo2Ice satellite observations

• Main Authors: Saha, Monojit, Stroeve, Julienne, Isleifson, Dustin, Yackel, John, Nandan, Vishnu, Landy, Jack Christopher, Lam, Hoi Ming
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2023
• Subjects: article; Verlagsveröffentlichung; Arctic; Canadian Arctic Archipelago; Arctic Archipelago; Sea ice
• Online Access: https://doi.org/10.5194/egusphere-2023-2509; https://noa.gwlb.de/receive/cop_mods_00069892; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068260/egusphere-2023-2509.pdf; https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2509/egusphere-2023-2509.pdf

Observations of snow on Arctic sea ice are vitally important for sea ice thickness estimation as well as for understanding bio-physical processes and human-activities. This study is the first assessment of the potential for near-coincident ICESat-2 and Cryosat-2 (Cryo2Ice) snow depth retrievals in a lead-less region of the Canadian Arctic Archipelago. Snow depths are retrieved using the absolute difference in surface height from a near-coincident ICESat-2 and Cryosat-2 after applying an ocean tide correction between satellite passes 77 minutes apart. Both the absolute mean snow depths and snow depth distributions retrieved from Cryo2Ice compare favourably to in-situ measurements. All four in-situ sites had snow with saline basal layers and different levels of roughness/ridging. The retrieved Cryo2Ice snow depths were underestimated by an average of 20.7 % which is slightly higher than the tidal adjustment applied. Differences in the Cryo2Ice and in-situ snow depth distributions reflected the different sampling resolutions between the sensors and the in-situ measurements, with more heavily ridged areas producing larger mean underestimation of the snow depth. Results suggest the possibility of estimating snow depth over lead-less landfast sea ice but attributing 2–3 cm biases to differences in sampling resolution, snow salinity, density, surface roughness and/or errors in altimeter’s tidal corrections require further investigation.