Our colleague Charlotte Durand has implemented the first 4D-Var for Arctic-wide sea-ice thickness forecasting using a differentiable emulator that she previously built. She demonstrates the capabilities of her 4D-Var system in twin experiments, as well as with real CS2SMOS satellite retrievals. The forecasts of our 4D–Var system achieve a similar performance as the operational sea-ice forecasting system neXtSIM-F.

The paper is entitled Four-dimensional variational data assimilation with a sea-ice thickness emulator, is published in The Cryosphere. The full text is in open access.