Revealing the nature of radar reflections in ice: DEP-based FDTD forward modeling

[1] Successful simulation of ground penetrating radar (GPR) traces in polar ice is achieved by numerical finite-difference time-domain (FDTD) forward modeling. Properties of the modeled medium are taken from high resolution dielectric profiling (DEP) of the upper 100 m of an ice core from Dronning Maud Land, Antarctica. The GPR reference trace is calculated from stacking of a normal moveout corrected common-midpoint survey, carried out near the borehole location. The excellent agreement of synthetic and GPR-based results demonstrates the capability of FDTD models to reproduce radargrams from ice core properties for interpretation of radio echo sounding data, and emphasizes the exploitation of radar data for improved interpretations of glaciological climate proxys. In addition to presenting modeling results, we perform sensitivity experiments to investigate the nature and origin of radar reflection in ice, discuss reasons for the failure of modeling studies in the past, and indicate new approaches.