Polarimetric Decomposition of Fully Polarimetric Synthetic Aperture RADAR to Examine Freshwater Lake Ice Microwave Backscatter Behaviour

Abstract

Lake ice, a critical component of the cryosphere, plays an essential role in climate regulation, freshwater availability, and the socio-economic stability of northern communities. Despite its importance, the interaction between lake ice and microwave signals remains insufficiently understood, particularly regarding how average lake depth influences microwave backscatter behavior. This study systematically analyzed fully polarimetric C-band, X-band, and L-band SAR data across multiple sites to determine the dominant scattering mechanisms driving lake ice backscatter. The findings demonstrate that single-bounce scattering is the predominant mechanism across all studied sites, irrespective of lake depth and wavelength, aligning with recent research that challenges traditional assumptions about the role of tubular bubbles in backscatter enhancement. These results have refined our understanding of SAR-based lake ice backscatter, paving the wave for more tangible microwave-based lake ice monitoring techniques. By advancing knowledge of microwave-ice interactions, this research enhances remote sensing applications for cryospheric studies and provides critical insights into lake ice dynamics under changing climatic conditions.