Multi-frequency polarimetric microwave observations of snow cover on first-year Arctic sea ice

This study explores the potential of a multi-frequency (Ku-, X- and C-band) scatterometry approach, to understand microwave interactions between teo statistically different snow thickness covers (14cm and 8cm) on first-year Arctic sea ice during the late winter to early-melt season transition. The results show substantial differences in backscatter response from all three frequencies, for both snow covers. Highly-saline snow covers with fluctuating snow geophysical and thermodynamic properties cause these backscatter fluctuations, with contributions from surface and volume scattering from different snow layers and interfaces. C-band exhibited drastic variations in backscatter, especially for the 14cm snow cover, when compared to Ku- and X-band. In the case of 8cm snow cover, all the three frequencies show minimal sensitivity to snow electro-thermo-physical properties. Our results show distinctly different snow thermodynamic processes operating within the different snow layers, essential for snow thickness estimation on first-year sea ice using active microwave remote sensing approaches.