Quantifying C-band scattering mechanisms from snow-covered first-year sea ice at the winter-spring transition

摘要

We present model and measurement results for time-series C-band normalized radar cross-sections (NRCS) over first-year snow-covered sea ice during a winter-spring transition period. Experimental scatterometer and physical data were collected near Cambridge Bay, Nunavut, Canada between May 20 and May 28, 2014 covering a severe storm event on May 25. We observed good agreement between model and experimental HH and VV NRCS. Before the storm, the large-scale surface scattering and volume scattering components dominated. After the storm, the large-scale scattering contribution increased, while the volume scattering contribution considerably dropped. Surface scattering from the small-scale component of the air-snow interface became significant at high incidence angles. We attribute these effects to the increase in surface roughness and snow moisture content during the post-storm period. Our results provide a physical basis for interpretation of time-series SAR images over sea ice at the winter-spring transition.