Multi-frequency altimetry snow depth estimates over heterogeneous snow-covered Antarctic summer sea ice – Part 1: C∕S-, Ku-, and Ka-band airborne observations

Fredensborg Hansen, Renée Mie; Skourup, Henriette; Rinne, Eero; Jutila, Arttu; Lawrence, Isobel R.; Shepherd, Andrew; Høyland, Knut Vilhelm; Li, Jilu; Rodriguez-Morales, Fernando; Simonsen, Sebastian Bjerregaaard; Wilkinson, Jeremy; Veyssiere, Gaelle; Yi, Donghui; Forsberg, René; Casal, Taniâ Gil Duarte

doi:https://doi.org/10.5194/tc-19-4167-2025

Articles | Volume 19, issue 10

https://doi.org/10.5194/tc-19-4167-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/tc-19-4167-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 10

Research article

|

02 Oct 2025

Research article |

| 02 Oct 2025

Multi-frequency altimetry snow depth estimates over heterogeneous snow-covered Antarctic summer sea ice – Part 1: C∕S-, Ku-, and Ka-band airborne observations

Renée Mie Fredensborg Hansen, Henriette Skourup, Eero Rinne, Arttu Jutila, Isobel R. Lawrence, Andrew Shepherd, Knut Vilhelm Høyland, Jilu Li, Fernando Rodriguez-Morales, Sebastian Bjerregaaard Simonsen, Jeremy Wilkinson, Gaelle Veyssiere, Donghui Yi, René Forsberg, and Taniâ Gil Duarte Casal

Data sets

Airborne ellipsoidal elevations and derived snow depths from Ka-, Ku-, C/S-band and lidar observations along CRYO2ICEANT22 under-flight (13 December 2022) along co-located CRYO2ICE (CryoSat-2 and ICESat-2) observations of snow depth using CryoTEMPO, FF-SAR and ESA-E CryoSat-2 processing chains Renée Mie Fredensborg Hansen et al. https://doi.org/10.11583/DTU.26732227

CS2EO ESA http://www.cs2eo.org

ERA5 hourly data on single levels from 1940 to present H. Hersbach et al. https://doi.org/10.24381/cds.adbb2d47

A Simulation of Snow on Antarctic Sea Ice Based on Satellite Data and Climate Reanalyses (http://www.cpom.ucl.ac.uk/cassis/) I. R. Lawrence et al. https://doi.org/10.1029/2022JC019002

AMSR-E/AMSR2 Unified L3 Daily 12.5 km Brightness Temperatures, Sea Ice Concentration, Motion & Snow Depth Polar Grids W. N. Meier et al. https://doi.org/10.5067/RA1MIJOYPK3P

Model code and software

CRYO2ICEANT2022 Antarctic Summer Sea Ice Under-Flight using Multi-Frequency Airborne Altimetry Renée Mie Fredensborg Hansen https://doi.org/10.5281/zenodo.13749342

Short summary

An airborne campaign collected unprecedented coincident multi-frequency radar and lidar data over sea ice along a CryoSat-2 and ICESat-2 (CRYO2ICE) orbit in the Weddell Sea, useful for evaluating microwave snow penetration. Ka-band and Ku-band had limited penetration with significant contributions from the air–snow interface, contradicting traditional assumptions with discrepancies between commonly used C/S-band "snow-radar" methodologies, all challenging comparisons of airborne and spaceborne estimates.