DEF (Diffusion-augmented Ensemble Forecasting) is a new approach for generating initial condition perturbations.
It aims to address limitations in existing methods primarily designed for numerical weather prediction solvers, making them less applicable to machine learning for weather prediction.
DEF utilizes a simple conditional diffusion model to generate structured perturbations iteratively, with a guidance term for controlling the perturbation level.
Validation on the ERA5 reanalysis dataset shows that DEF improves predictive performance and provides reasonable spread estimates for long-term forecasts.