๐ค AI Summary
In data assimilation, uncertainty quantification remains challenging due to the coupling of dynamical models with process noise and sparse, noisy observations. To address this, we propose a variational inferenceโbased uncertainty-aware data assimilation framework that models stochastic state evolution as a multivariate Gaussian distribution, enabling approximately perfectly calibrated uncertainty estimates and supporting longer assimilation windows. The method is end-to-end differentiable and seamlessly embeddable within machine learning architectures. Evaluated on the chaotic Lorenz-96 system, it achieves high state estimation accuracy while significantly improving uncertainty calibration and out-of-distribution generalization compared to conventional approaches. All code is publicly available to facilitate reproducibility and further research extensions.
๐ Abstract
Data assimilation, consisting in the combination of a dynamical model with a set of noisy and incomplete observations in order to infer the state of a system over time, involves uncertainty in most settings. Building upon an existing deterministic machine learning approach, we propose a variational inference-based extension in which the predicted state follows a multivariate Gaussian distribution. Using the chaotic Lorenz-96 dynamics as a testing ground, we show that our new model enables to obtain nearly perfectly calibrated predictions, and can be integrated in a wider variational data assimilation pipeline in order to achieve greater benefit from increasing lengths of data assimilation windows. Our code is available at https://github.com/anthony-frion/Stochastic_CODA.