Microwave Radiometry Improves Modelling of Surface Melt Processes of Antarctic Firn

Abstract. Surface melt strongly influences the thermodynamics and stability of Antarctic ice shelves, yet firn models remain poorly constrained due to scarce observations. We present a framework that integrates satellite-borne microwave radiometry with firn modelling to evaluate meltwater generation and infiltration. Using the Glacier Energy and Mass Balance (GEMB) surface energy balance model, we simulate snow and firn temperature, density, and liquid water content (LWC) on the Shackleton Ice Shelf. These outputs drive the Microwave Emission of Model of Layered Snowpacks (MEMLS) radiative transfer model to simulate microwave brightness temperatures (TB), which we compare with satellite radiometer observations at 1.4 and 36.5 GHz. Because TB is highly sensitive to LWC, this approach provides a powerful constraint on firn thermodynamics in data-sparse regions. Our results reveal that realistic simulation of meltwater percolation and refreezing requires substantially finer vertical resolution than typically employed. Incorporating radiometric constraints thus improves firn evolution modelling and advances projections of Antarctic ice shelf stability.