Feasibility study into ice sheet-ocean model initialisation (Deliverable D3.4)

This deliverable describes a feasibility study into using Ensemble Kalman Inversion to initialise coupled Ice-Ocean Models. A manuscript describing the technical details of the research has been submitted to The Cryosphere (Bradley et al. https://doi.org/10.5194/egusphere-2025-2315). This report provides a brief introduction to the methods used and illustrative results from the submitted manuscript. Additionally, we provide links to public code repositories where examples of the methods are implemented, along with relevant code snippets. In performing this feasibility study, we have made four key findings:

●        Ensemble Kalman Inversion (EKI) can be successfully used to constrain parameters in ice-sheet models with simplified ocean-driven melting schemes, making the approach feasible.

●        EKI can be deployed effectively as part of a Calibrate-Emulate-Sample (CES) strategy.

●        Combining EKI and CES allows probabilistic assessment of parameters.

●        This, in turn, will allow uncertainty quantification, probabilistic attribution studies, and forecasts of the risk posed by marine ice sheets.