Analysis of backscattering from snow covers on Arctic and Antarctic sea ice

摘要

A multilayer scattering model for snow covered sea ice is utilized in the analysis of backscattering from the snow-covered Arctic and Antarctic sea ice. The multilayer model accounts for full incoherent interactions inside the snow and sea ice layers. The rough boundaries are modeled using the IEM surface model. Model computations are carried out using the available ground truth information obtained at the measurement sites. Good agreement between model and data is obtained in both the Arctic and Antarctic snow-covered sea ice cases. Preliminary analysis of the backscattering measurements from Antarctic snow-covered sea ice indicates that the signature is dominated by scattering from the snow-ice interface and attenuation through snow. This is due to the high salinity of the bottom portion of the snow layer and the presence of slush at the snow-ice interface which are indicated in the ground truth information. The backscattering signature of Arctic snow-covered sea ice, on the other hand, consists of contribution from snow-ice interface, the snow layer, and the bubbly ice underneath. The snow cover of Arctic sea ice is generally very low in salinity and the average ice particle size in the Arctic snow cover is also smaller than the average size of the Antarctic snow cover. At X-band, the backscattering contribution from the Arctic snow layer is significant only at large incident angles.