Retrieval of Snow Depth on Arctic Sea Ice From Surface-Based, Polarimetric, Dual-Frequency Radar Altimetry

• Published in: Geophysical Research Letters
• Main Authors: Willatt, Rosemary, Stroeve, Julienne, Nandan, Vishnu, Newman, Thomas, Mallett, Robbie, Hendricks, Stefan, Ricker, Robert, Mead, James, Itkin, Polona, Tonboe, Rasmus, Wagner, David N., Spreen, Gunnar, Liston, Glen, Schneebeli, Martin, Krampe, Daniela, Tsamados, Michel, Demir, Oguz, Wilkinson, Jeremy, Jaggi, Matthias, Zhou, Lu, Huntemann, Marcus, Raphael, Ian A., Jutila, Arttu, Oggier, Marc
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Arctic; Sea ice
• Online Access: https://hdl.handle.net/10037/31946; https://doi.org/10.1029/2023GL104461

Snow depth on sea ice is an Essential Climate Variable and a major source of uncertainty in satellite altimetry-derived sea ice thickness. During winter of the MOSAiC Expedition, the “KuKa” dual-frequency, fully polarized Ku- and Ka-band radar was deployed in “stare” nadir-looking mode to investigate the possibility of combining these two frequencies to retrieve snow depth. Three approaches were investigated: dual-frequency, dual-polarization and waveform shape, and compared to independent snow depth measurements. Novel dual-polarization approaches yielded r 2 values up to 0.77. Mean snow depths agreed within 1 cm, even for data sub-banded to CryoSat-2 SIRAL and SARAL AltiKa bandwidths. Snow depths from co-polarized dual-frequency approaches were at least a factor of four too small and had a r 2 0.15 or lower. r 2 for waveform shape techniques reached 0.72 but depths were underestimated. Snow depth retrievals using polarimetric information or waveform shape may therefore be possible from airborne/satellite radar altimeters.