Multi-frequency studies of snow and sea ice: A combined remote sensing and modelling investigation aiming to reduce biases in polar sea ice thickness

Sea ice is an important component of the earth system as it acts to cool the planet whilst regulating the exchange of momentum, heat and moisture between the atmosphere and ocean. The snowpack that accumulates upon sea ice both impacts the evolution of the ice below and hinders our ability to accurately retrieve its thickness from space. But despite the two forming an inherently coupled system, snow-on-sea-ice remains poorly understood. The layered snowpack currently biases sea ice thickness retrievals from radar (microwave) altimeters by: (1) slowing down radar-wave propagation, (2) changing the radar-wave dominant scattering horizon, and (3) changing the hydrostatic equilibrium of the system, thus altering sea ice freeboard. In this project, I will take an approach that combines satellite remote sensing of sea ice in different frequencies of electromagnetic radiation and using different techniques (i.e., active and passive remote sensing) to provide more accurate estimations of the depth of the snow layer and its properties. These studies will be backed by investigations using physics-based models to simulate electromagnetic scattering under different physical scenarios which can help us to understand how a multi-frequency approach can ultimately reduce biases in snow/sea ice thickness estimations.