Physical Interpretation of Microwave Emission From Snow-Covered Stratified Sea Ice With Rough Boundaries

• Published in: IEEE transactions on geoscience and remote sensing Vol. 63; pp. 1 - 17
• Main Authors: Yang, Ying, Chen, Kun-Shan, Atli Benediktsson, Jon, Orn Ulfarsson, Magnus
• Format: Journal Article
• Language: English
• Published: New York IEEE 2025; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Atmospheric modeling; Boundaries; Brightness; Brightness temperature; Eigenvalues; Emissions; First-year (FY) ice; gradient ratio (GR); Ice; Ice cover; Microwave emission; Microwave FET integrated circuits; Microwave integrated circuits; Microwave theory and techniques; multiyear (MY) ice; Ocean temperature; Polarization; polarization ratio (PR); Radiative transfer; rough boundary; Roughness; Scattering; Sea ice; Sea surface; Snow; Snow cover; Surface radiation temperature
• DOI: 10.1109/TGRS.2025.3544636
• ISSN: 0196-2892

This study examines the microwave emission properties of snow-covered sea ice, modeled as a layer with rough top and bottom boundaries. The emission model is based on the first-order solution to the radiative transfer equation (RTE). This equation describes the brightness temperatures that propagate both upward and downward in the layer, and it is solved numerically using the eigenvalue method. Additionally, the model takes into account contributions from irregular boundaries as well as surface and volume scattering interactions. The study looks at the variability of brightness temperature and the growth of different ice types. It uses modulation theory to consider the roughness of the boundaries, showing how this affects the emission from various types of snow-covered sea ice. We used polarization ratio-gradient ratio (PR-GR) space to analyze ice-grown transitions quantitatively. The thresholds of PR were found to be sensitive to changes in ice concentration. It was observed that the threshold of PR did not change with the roughness of the top boundary. We also found that the roughness of the ice surface has a more significant impact on emission than that of the snow-covered ice. It also observed that roughness effects are more potent in H-polarization than in V-polarization for each of the seven ice types. The roughness effects are weaker at large look angles, indicating stronger volume scattering. The study concludes that the presence of roughness in the ice layer's boundaries leads to noticeable variations in brightness temperature.