Simulating Multifrequency Ground-Based Radiometric Measurements at Dome C-Antarctica

Recent interest by the research community in investigating Antarctica at low microwave frequency is stimulated by the availability of new satellite-borne radiometers. Special attention has been paid to the Dome C region of the East Antarctic Plateau, which was selected by the European Space Agency (ESA) as a calibration and validation test site for the soil moisture and ocean salinity (SMOS) mission. In order to support this mission and better characterize the site, several surface and airborne campaigns were conducted. Analysis of microwave measurements collected by ground-based radiometers at Dome C during the DOMEX experiments reveals that ice-sheet parameter-profiles have a significant impact on the microwave emission even at low frequencies. In order to assess this observation, a theoretical analysis of microwave emission was carried out using the multilayer dense medium radiative transfer theory under the quasi-crystalline approximation with coherent potentials and ice-sheet geophysical-parameter profiles (i.e., temperature, density, layering, and grain size) collected in the Dome C area. The electromagnetic model was used to fit the angular distribution of microwave observations collected at C- and L-bands at Dome C. The analysis identifies the variability in the snow density vertical profile as a major factor in determining the microwave signature of the snow emission at both L- and C-bands. A secondary role is played by the snow grain radius profile that appreciably influences C-band.