New Opportunities for Antarctic Science with ESA’s BIOMASS Mission

Kurzfassung

Launched in April 2025, ESA’s BIOMASS mission operates a P-band (435 MHz) Synthetic Aperture Radar, enabling innovative subsurface mapping due to the signal penetration into firn and ice, as well as the mission’s polarimetric and interferometric capabilities. This contribution presents examples from Antarctica, demonstrating the potential to characterize ice-sheet subsurface properties. A first example are Antarctica-wide maps of polarimetric observables, which highlight complex scattering from shear margins, but also reveal spatial patterns in the rather homogeneous interior of the ice sheet. We analyze acquisitions over the Riiser-Larsen ice shelf in more detail. There, polarimetric anisotropy patterns appear in regions of disturbed ice flow, corresponding to transitions from continuous to folded stratigraphy. Scattering modelling relates this anisotropy to deformation-induced reorganization of subsurface scatterers. These findings suggests that continent-wide BIOMASS data can map shear-induced subsurface deformation. As a second example, the polarimetric signatures of tabular icebergs floating off the coast of Antarctica were among the most distinctive ones observed during the in-orbit commissioning phase. In addition to the response of the iceberg itself, a time-delayed replica appears as the result of scattering interactions at the icebergs' base. We used polarimetric analyses and a simple geometric model to investigate the scattering mechanisms at the top and base of icebergs. Their relative range displacement is related to the iceberg thickness and indicates a potential penetration depth of the P-band signal in firn and ice of more than 250–300 m. Collectively, these results demonstrate BIOMASS’s unique potential to image subsurface structures of Antarctic ice.