Synoptic Variability in Satellite Altimeter‐Derived Radar Freeboard of Arctic Sea Ice

Carmen Nab*, Robbie Mallett, William Gregory, Jack Landy, Isobel Lawrence, Rosemary Willatt, Julienne Stroeve, Michel Tsamados

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Satellite observations of sea ice freeboard are integral to the estimation of sea ice thickness. It is commonly assumed that radar pulses from satellite-mounted Ku-band altimeters penetrate through the snow and reflect from the snow-ice interface. We would therefore expect a negative correlation between snow accumulation and radar freeboard measurements, as increased snow loading weighs the ice floe down. In this study we produce daily resolution radar freeboard products from the CryoSat-2 and Sentinel-3 altimeters via a recently developed optimal interpolation scheme. We find statistically significant (p < 0.05) positive correlations between radar freeboard anomalies and modeled snow accumulation. This suggests that, in the period after snowfall, radar pulses are not scattering from the snow-ice interface as commonly assumed. Our results offer satellite-based evidence of winter Ku-band radar scattering above the snow-ice interface, violating a key assumption in sea ice thickness retrievals.
Original languageEnglish
Article numbere2022GL100696
Number of pages11
JournalGeophysical Research Letters
Issue number2
Early online date9 Jan 2023
Publication statusPublished - 28 Jan 2023
Externally publishedYes

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